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Clark University 

1889-1899 

decennial Celebration 




Worcester, Mass. 

Printed for the University 

1899 



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COPTEIOHT, 1899, 

By CLARK UmtVERSITy. 



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Korinooti ^nss 

J. 8. Cnshing S Co. — Berwick & Smith 
Norwood, Mass. U. S. A. 



PEEFACE. 

This volume is intended not only to commemorate the Decen- 
nial Anniversary of Clark University, but also to make the Public 
acquainted with its aims and ideals, and with the character, scope, 
and amount of the work it has already done. Ever since it 
opened its doors to students it has confined itself to truly post- 
graduate work in a few departments, and has admitted such 
students only as gave promise of the ability not only to pursue 
the courses here offered with advantage to themselves, but to 
benefit the world by advancing science along the lines here repre- 
sented. It has thus taken a distinct position as a training school 
for college professors and scientific investigators. Such a policy 
is conducive neither to large numbers of students nor to popular 
appreciation. But, small as the university is and few as are its 
departments, it takes great satisfaction in pointing to this volume 
as, in some sense, a record of its work and its methods. The 
list of titles of the publications of its past and present members 
is a witness of the quality and quantity of what it has accom- 
plished. We beheve that Clark University, opening, as it did, 
at the beginning of a new university epoch in this comitry, has 
had some special influence in suggesting new lines of scientific 
research. 

The five foreign professors who took part in the Decennial 
Celebration were selected as the most eminent available scientific 
men in their respective lines in Europe ; this was the first visit of 
each to America, and four of them came here solely for this anni- 



iv Preface. 

versary. Their lectures are here ^(^^roduced in extenso and have 
not been published elsewhere. T lectures of Professors Picard 
and Bolt' "^n are given in the languages in which they were 
delivered, and those of Professors Kamdn y Cajal, Mosso, and 
Forel in translations made by members of the Faculty and revised 
by representatives of the departments to which they severally 
belong. For these laborious services the editors desire to extend 
their very particular thanks to the individuals who have rendered 
them. 

The reports of departments were prepared especially for this 
occasion, and include not only an account of the work actually 
done during the decade, but also a statement by the officer in 
charge of each department of its aims and ideals and the lines 
along which it hopes to advance. The responsibility for the 
content and form of each report rests with the individual in 
whose name it is published ; all modifications by the editors hav- 
ing been made in the form of suggestions to the writers and 
adopted only with their consent. It is perhaps unnecessary to 
say that no attempt has been made to secure uniformity in the 
various articles, excepting in the titles and in minor details of 
arrangement. 

The editors extend their hearty thanks to the authors of the 
several portions of the volume for their cordial cooperation and 
for the friendly spirit in which suggestions have been received, 
and to all members of the Faculty for assistance in reading the 
proof-sheets. 

WILLIAM E. STORY, 
LOUIS N. WILSON, 

Editors. 



TABLE OF COI^TEJ^TB 

PAGE 

HISTOEICAL SKETCH 1 

THE DECENNIAL CELEBRATION 13 

EXTRACTS FROM CONGRATULATORY LETTERS ... 26 

DECENNIAL ADDRESS 45 

By G. Stanley Hall, President of the University. 

EEPORTS OF DEPAETMENTS 

THE DEPARTMENT OF MATHEMATICS 61 

By William Edwakd Stort. 

THE DEPARTMENT OF PHYSICS 85 

By Arthur Gordon Webster. 

THE DEPARTMENT OF BIOLOGY 99 

By Clifton F. Hodge. 

THE DEPARTMENT OF PSYCHOLOGY 119 

General Psychology 122 

By Edmund C. Sanford. 

Psycho-Pathology 144 

By Adolf Meter. 

Anthropology 148 

By Alexander F. Chamberlain. 

Pedagogy 161 

By William H. Burnham. 

Philosophy 177 

By G. Stanley Hall. 

THE LIBRARY 187 

By Louis N. Wilson. 

REPORT OF THE TREASURER 199 

By Thomas H. Gage. 



Table of Contents 



SCIENTIFIC LECTURES 

DELIVERED IN CONNECTION WITH THE 
DECENNIAL CELEBRATION 

PAGE 

^MiLE PicARD, Professor of Mathematics at the University of Paris. 

1. Sur I'Extension de quelques Notions Mathematiques, et en parti- 

culier de I'Idee de Fonction depuis un Siecle .... 207 

2. Quelques Vues Generales sur la Theorie des liquations Differentielles 224 

3. Sur la Theorie des Fonctions Analytiques et sur quelques Fonc- 

tions Speciales 241 

LuDwiG BoLTZMANN, Professor of Theoretical Physics at the University of 
Vienna. 
Ueber die Grundprincipien und Grundgleicliuugen der Mechanik. 

(Four Lectures) 261 

Sajsttiago Eamon y Cajal, Professor of Histology and Hector of the 
University of Madrid. 

1. Comparative Study of the Sensory Areas of the Human Cortex . 311 

2. Layer of the Large Stellate Cells 336 

3. The Sensori-Motor Cortex 360 

Angelo Mosso, Professor of Physiology and Rector of the University of 
Turin. 

1. Psychic Processes and Muscular Exercise 383 

2. The Mechanism of the Emotions 396 

August Foeel, Late Professor of Psychiatry at the University of Zilrich 
and Director of the Burgholzli Asylum. 

1. Hypnotism and Cerebral Activity 409 

2. A Sketch of the Biology of Ants 433 

DEGREES CONFERRED, 1889-1899 453 

TITLES OF PUBLISHED PAPERS ....... 459 

SPECIAL STUDENTS . . . 565 



HISTORICAL SKETCH. 



HISTORICAL SKETCH. 



Claek University was founded by the munificence of Jonas G. Clark, 
a native of Worcester County, whose plans, conceived more than twenty 
years before, had gradually grown vnth his fortune. His affairs had been 
so arranged as to allow long intervals for travel and study. During 
eight years thus spent, the leading foreign institutions of learning, old 
and new, were visited, and their records gathered and read. These 
studies centred about the means by which the highest culture of one 
generation is best transmitted to the ablest youths of the next, and 
especially about the external conditions most favorable for increasing 
the sum of human knowledge. To the improvement of these means and 
the enlargement of these conditions, the new University was devoted. 

It was the strong and express desire of the founder that the highest 
possible academic standards be here forever maintained ; that special 
opportunities and inducements be offered to research ; that to this end the 
instructors be not overburdened with teaching and examinations ; that 
all available experience, both of older countries and oiu" own, be freely 
utilized ; and that new measures, and even innovations, if really helpful 
to the highest needs of modern science and culture, be no less freely 
adopted ; in fine, that the great opportimities of a new foundation in this 
land and age be diligently explored and improved. 

He chose Worcester as the seat of the new foundation after mature 
deliberation, — first. 

Because its location is central among the best colleges of the East, and 
by supplementing rather than duplicating their work, he hoped to ad- 
vance all their interests and to secure their good will and active support, 
that together they might take further steps in the development of 
superior education in New England ; and secondly, 

Because he believed the culture of this city would insure that en- 
lightened public opinion indispensable in maintaining these educational 



2 Historical Sketch. 

standards at their highest, and that its wealth would insure the perpetual 
increase of revenue required by the rapid progress of science. 

As the first positive step toward the realization of these long-formed 
plans, Mr. Clark invited the following gentlemen to constitute with 
himself a Board of Trustees : — 
Stephen Salisbury, A.B., Harvard, 1856; Universities of Paris and Berlin, 

1856-58; LL.B., Harvard, 1861; President Antiquarian Society since 1887; 

State Senator, 1892-95. 
Charles Dbvens, A.B., Harvard, 1838 ; LL.B., Harvard, 1840 ; Major-General, 

1863 ; Associate Justice of the Massachusetts Superior Court, 1867-73 ; 

Associate Justice of the Massachusetts Supreme Judicial Court, 1873-77, 

and again, 1881-91; Attorney-General of the United States, 1877-81; 

LL.D., Cohunbia and Harvard, 1877; Died January 7, 1891. 
George P. Hoar, A.B., Harvard, 1846 ; LL.B., Harvard, 1849 ; United States 

House of Kepresentatives, 1869-77 ; Member Electoral Commission, 1876 ; 

United States Senate since 1877 ; Chairman of Judiciary Committee, 1891 — ; 

LL.D., William and Mary, Amherst, Harvard, and Tale. 
William W. Kice, A.B., Bowdoin, 1846 ; admitted to Bar, 1854 ; United States 

House of Representatives, 1876-86; LL.D., Bowdoin, 1886. Died March 1, 

1896. 
Joseph Sargent, A.B., Harvard, 1834 ; M.D., Harvard, 1837 ; London and Paris 

Hospitals, 1838-40. Died October 13, 1888. 
John D. Washburn, A.B., Harvard, 1853; LL.B., Harvard, 1856; Representa- 
tive, 1876-79 ; State Senate, 1884 ; United States Minister to Switzerland, 

1889-92. 
Frank P. Goulding, A.B., Dartmouth, 1863 ; Harvard Law School, 1866 ; 

City Solicitor, 1881-93. 
George Swan, A.B., Amherst, 1847 ; admitted to Bar, 1848 ; Member of 

Worcester School Board, 1879-90; Chairman of High School Committee, 

1887-90. 

The following gentlemen have been added to the Board since to fill 
vacancies caused by death. In place of Dr. Sargent : — 
Edward Cowles, A.B., Dartmouth, 1869; M.D., Dartmouth, 1862, and Col- 
lege of Physicians and Surgeons, IST. Y., 1863 ; Assistant Surgeon, U. S. A., 
1863-72 ; Resident Physician and Superintendent Boston City Hospital, 
1872-79 ; Medical Superintendent McLean Asylum since 1879 ; Professor of 
Mental Diseases, Dartmouth Medical School, since 1885 ; Clinical Instructor 
in Mental Diseases, Harvard Medical School, since 1888. 

In place of General Devens: 

Thomas H. Gage, M.D., Harvard, 1852; President Massachusetts Medical 
Society, 1886-88. 



Historical Sketch. 3 

On petition of this Board, the Legislature passed tlie following 

Act of Incorpokation. Chapter 133. 

commonwealth op massachusetts, in the tear one thousand eight hun- 
dred and eighty-seven. an act to incorporate the trustees of 
clark university in worcester. 

Be it enacted by the Senate and House of Representatives in General Court 
assembled, and by authority of the same, as follows : — 

Section 1. Jonas G. Clark, Stephen Salisbury, Charles Devens, George F. 
Hoar, William W. Rice, Joseph Sargent, John D. Washburn, Frank P. Gould- 
ing and George Swan, all of the city of Worcester, in the Commonwealth of 
Massachusetts, and their successors, are hereby made a corporation by the name 
of the Trustees of Clark University, to be located in said Worcester, for the 
piu'pose of establishing and maintaining in said city of Worcester an institu- 
tion for the promotion of education and investigation in science, literature and 
art, to be called Clark University. 

Section 2. Said corporation may receive and hold real or personal estate 
by gift, grant, devise, bequest or otherwise, for the purpose aforesaid, and shall 
have all the rights, privileges, immunities, and powers, including the conferring 
of degrees, which similar incorporated institutions have in this Commonwealth. 

Section 3. Said corporation shall have the power to organize said Univer- 
sity in all its departments, to manage and control the same, to appoint its 
ofB.cers, who shall not be members of said corporation, and to fix their com- 
pensation and their tenure of oifice ; and said corporation may provide for the 
appointment of an advisory board and for the election by the Alumni of said 
University to fill any vacancies in said board. 

Section 4. The number of members of said corporation shall not be less 
than seven nor more than nine, and any vacancy therein may be filled by the 
remaining members at a meeting duly called and notified therefor ; and when any 
member thereof shall, by reason of infirmity or otherwise, become incapable, in 
the judgment of the remaining members, of discharging the duties of his office, 
or shall neglect or refuse to perform the same, he may be removed and another 
be elected to fill his place, by the remaining members, at a meeting duly called 
and notified for that purpose. 

Section 5. This Act shall take effect upon its passage. 

House of Representatives, March 30, 1887, Passed to be Enacted. 

Charles J. Notes, Speaker. 
Senate, March 31, 1887, Passed to be Enacted. 

Halset J. BoARDMAN, President. 

During the previous five years, Mr. Clark had gradually acquired a 
tract of land, comprising over eight acres, located on Main Street, about 



4 Historical Sketch. 

a mile from the heart of the city, with additional tracts near by. This 
land has considerable elevation above that part of the city, is a watershed 
sloping to the southeast, insuring sanitary excellence and a wide and 
picturesque view. A park reservation of about 25 acres, directly oppo- 
site, has been set apart by the city, and named University Park. 

Plans for a main building were submitted to the Board by Mr. Clark, 
which were approved, and its erection was at once begun. The corner- 
stone was laid with impressive ceremonies, October 22, 1887. This build- 
ing is plain, substantial, and well appointed, 204 x 114 feet, four stories high 
and five in the centre, with superior facilities for heating, lighting, and 
ventilation, and has been constructed of brick and granite, and finished 
throughout in oak. On the whole it is a model of stability and solid work- 
manship. It contains a total of 90 rooms, and in its tower is a clock with 
three six-foot illuminated dials, which was presented by the citizens of 
Worcester. The elevations and ground plan are published, and the heat- 
ing, lighting, ventilation, walls, floors, etc., etc., are described in detail 
in the Third Official Announcement. 

On April 3, 1888, G. Stanley Hall, then a professor at Johns 
Hopkins University, was invited to the presidency. The official letter 
conveying the invitation to the president contained the following well-con- 
sidered and significant expression of the spirit animating the trustees : — 

" They desire to impose on you no trammels ; they have no friends for whom 
they wish to provide at the expense of the interests of the institution ; no pet 
theories to press upon you in derogation of your judgment ; no sectarian tests 
to apply ; no guarantees to require, save such as are implied by your acceptance 
of this trust. Their single desire is to fit men for the highest duties of life, 
and to that end, that this institution, in whatever branches of sound learning 
it may find itself engaged, may be a leader and a light." 

This invitation was accepted May 1, and the president was at once 
granted one year's leave of absence, with full salary, to visit universities 
in Europe. This year was diligently improved in gathering educational 
literature and collecting information and advice from leading authorities. 
Many reports based upon this work have already been made in the Peda- 
gogical Seminary and more are in course of preparation. 

During the absence of the president a Chemical Laboratory was begun. 
This building in its main body has three stories, in its eastern wing four, 
in its southwestern two. It contains 68 rooms. The outer walls are 
2 feet in thickness and the partition walls from 12 to 16 inches. All par- 



Historical Sketch. 5 

titions are of brick, so that the building is nearly fireproof. The two 
large laboratories are 24x58 feet and 22 feet high. This building is 
also described with plans in the Third Official Announcement. 

The opening exercises were held in a hall of the University, seating 
1500 people, on Wednesday, October 2, 1889. The late General Charles 
Devens presided, and made an opening address. Addresses were made 
by Senator George F. Hoar and the president. The founder of the 
University stated his purpose as follows : — 

" When we first entered upon our work it was with a well-defined plan and 
purpose, in which plan and purpose we have steadily persevered, turning 
neither to the right nor to the left. We have wrought upon no vague concep- 
tions nor suffered ourselves to be borne upon the fluctuating and unstable 
current of public opinion or public suggestions. We started upon our career 
with the determinate view of giving to the public all the benefits and advan- 
tages of a university, comprehending full well what that implies, and feeling 
the full force of the general understanding, that a university must, to a large 
degree, be a creation of time and experience. We have, however, boldly 
assumed as the foundation of our institution the principles, the tests, and the 
responsibilities of universities as they are everywhere recognized — but with- 
out making any claim for the prestige or flavor which age imparts to all things. 
It has therefore been our purpose to lay our foundation broad and strong and 
deep. In this we must necessarily lack the simple element of years. We 
have what we believe to be more valuable — the vast storehouse of the knowl- 
edge and learning which has been accumulating for the centuries that have 
gone before us, availing ourselves of the privilege of drawing from this source, 
open to all alike. We propose to go on to further and higher achievements. 
We propose to put into the hands of those who are members of the University, 
engaged in its several departments, every facility which money can command 
— to the extent of our ability — in the way of apparatus and appliances that 
can in any way promote our object in this direction. To our present depart- 
ments we propose to add others from time to time, as our means shall warrant 
and the exigencies of the University shall seem to demand, always taking those 
first whose domain lies nearest to those already established, imtil the full 
scope and purpose of the University shall have been accomplished. 

"These benefits and advantages thus briefly outlined, we propose placing at 
the service of those who from time to time seek, in good faith and honesty of 
purpose, to pursue the study of science in its purity, and to engage in scientific 
research and investigation — to such they are offered as far as possible free 
from all trammels and hindrances, without any religious, political, or social 
tests. All that will be required of any applicant wUl be evidence, disclosed 
by examinations or otherwise, that his attainments are such as to qualify him 
for the position that he seeks." 



6 Historical Sketch. 

After careful consideration it was decided to begin with graduate 
work only and in the following five departments : 

I. Mathematics. 

II. Physics, ExiDcrimental and Theoretical. 

III. Chemistry, Organic, Inorganic, Physical, and Crystallography. 

IV. Biology, including Anatomy, Physiology, and Paleontology. 

V. Psychology, including Neurology, Anthropology, and Education. 

Mathematics is sometimes called the queen of all the sciences. As 
the latter become exact, they approximate it, and are fructified by its 
spirit and its methods. Its antiquity, its disciplinary value, its rapid 
and recent development, make it obviously indispensable. Physics is 
the field of the most immediate application of mathematics, and deals 
with the fundamental forces of the material universe, — heat, sound, 
light, electricity, — and the underlying problems of form and motion 
generally, with their vast field of application in such sciences as astronomy 
and dynamic geology. Chemistry, with its great and sudden development, 
revealing marvellous order and harmony in the constitution of matter, 
is rapidly extending its dominion over industrial processes. Biology, 
which seeks to fathom the laws of life, death, reproduction, and disease, 
that underlies all the medical sciences, in its broader aspects has taught 
man in recent decades far more concerning his origin and nature than all 
that was known before. Psychology, or the study of man's faculties 
and their education, is a new field into which all the sciences are bringing 
so many of their richest and best ideas, which is now so full of promise 
for the life of man. 

A sub-department of Education was established in 1892, and the 
department of Chemistry was temporarily discontinued in 1894. 

To express more explicitly the character and policy of the institution, 
the Trustees voted to approve and publish the following statement : — 

" As the work of the University increases, its settled policy shall be always 
to first strengthen departments already established, until they are as thorough, 
as advanced, as special, and as efficient as possible, before proceeding to the 
establishment of new ones. 

"When this is done and new departments are established, those shall always 
be chosen first which are scientifically most closely related to departments 
already established ; that the body of sciences here represented may be kept 
vigorous and compact, and that the strength of the University may always 
rest, not upon the number of subjects, nor the breadth or length of its cur- 
riculum, but upon its thoroughness and its unity. 



Historical Sketch. 7 

" This shall in no wise hinder the establishment, by other donors than the 
founder, of other and more independent departments if approved by the 
Trustees. 

" While ability in teaching shall be held of great importance, the leading 
consideration in all engagements, reappointments, and promotions shall be the 
quality and quantity of successful investigation." 

By thus limiting the work of the University in the beginning to 
five departments, it appeals only to advanced men who desire to specialize 
in one or more of these fundamental sciences, leaving college students 
who require a larger range of studies, as well as those who desire to 
devote themselves to language and literature, historical, technical, or pro- 
fessional studies, to go elsewhere. Hence oiix work must be post- 
graduate. This requires the best professors and apparatus, more books 
and journals, and necessitates a system of fellowships, scholarships, and 
provisions for original research. It thus becomes a training-school for 
professors. This is the most expensive of all educational work, seeks 
the fewest but the best men from the widest area, and to succeed must 
be helpful in elevating the academic standards of the country to a higher 
plane. It requires the highest degree of wisdom and foresight on the 
part of the Founder and the Trustees, and possibly some sacrifices of 
local sympathy and support at first, till the nature of the work is well 
understood. It requires the greatest eifort and devotion to work on 
the part of the Faculty and students. But the cause is itself an inspira- 
tion. It appeals to the future, the country, and to the world, and seeks 
quality more than nmnbers. It is in the current of all the best tenden- 
cies in the best lands, and is now the ideal of perhaps every eminent 
man of science everywhere. The inauguration and steady maintenance 
of this clear and simple policy gives the University a reason for being, 
and a distinct individuality it could not otherwise have, and also a real 
leadership in this epoch of awakening and transition, which is the golden 
time of opportunity for new institutions, and brings them to the front. 
Such a period as the present gives the latter even greater relative influ- 
ence and prominence than would be possible in periods of less public 
interest in education. New institutions can and should lead, set new 
fashions, and be the first upon the higher planes. Older institutions 
are retarded by conservatism and must advance more slowly, but 
when they move they carry great momentum. This condition makes 
the present a moment of perhaps unprecedented opportunity, which 



8 Historical Sketch. 

has been long looked for and long delayed, and which renders 
both funds and labor in this field more precious than they have 
been, or will be when it is past. We may all be content if our Uni- 
versity can transmit to future generations by means of its organization, 
plan, and methods the best and highest educational tendencies and move- 
ments now stirring the souls of the best men of the world, and uniting 
men of all lands, races, creeds, and stations in a larger if not also a deeper 
consensus of belief than history has ever known before. 

Our University does not draw its chief earnings from, or do most of 
its teaching for, undergraduates, and our so-called graduate students do 
not iake undergraduate courses. This makes the proportion of expendi- 
ture to income very high here, and indeed we can admit and do justice 
to but comparatively few students. Most of those who come here have 
spent one or more years after graduation in teaching, or in study in 
Europe or elsewhere. Most of those who have been members here have 
already obtained professorships or other academic positions elsewhere. 
The proportion of such is hardly excelled by the JEcole Normale of Paris, 
the special function of which is to train professors from other collegiate 
institutions. Every student who obtains original results is expected to 
present them in the form of lectures to his department, and thus to 
acquire experience in teaching under criticism. The work of the educa- 
tional department deals with problems and history of higher educational 
institutions, and is adapted to all the body of fellows and scholars, and 
seeks to increase the efficiency of every man both as a teacher of his own 
specialty and in general helpfulness to the institution with which he is to 
be connected. 

Since the opening of the University not less than five hundred books, 
memoirs, theses, or articles ^ have been published by members of the Uni- 
versity, which attempt to make additions to the sum of human knowledge. 
These contributions are of very different orders of value, but together they 
constitute a body of knowledge in which the institution takes special pride. 
Every member of the University is expected to make at least one long and 
serious effort of this kind. Indeed, had its publications no value as contri- 
butions to knowledge, its educational value is the highest for mature men. 
Such effort gets minds into independent action, gives a sense of authority 
and of true mental freedom, which no amount of acquisition can bring. It 
brings out new powers of mind and of will, and, while one of the chief 

1 A list of these publications will be found at the end of this volume. 



Historical Sketch. 9 

marks by which true University work is distinguished from that of lower 
grades, is in the line of all present tendencies to place doing above know- 
ing from the kindergarten up. Work that is published enlarges the 
sphere of interests of the author, subjects him to the higher test of being 
judged by his peers elsewhere, and brings in the potent and salutary 
stimulus of wider competition. This baptism of ink has often marked a 
new birth of ideals and ability in young men. Modern as distinct from 
earlier culture culminates in the man-making training of will and judg- 
ment thus given. Such work, too, gives teaching a new power and zest. 
Instruction to a fit few by an investigator who stands on the frontier and 
has once felt the light and heat in which discovery is wrought out is 
inspiring, and is very different from information imparted at lower levels 
by teachers further removed from the work of discovery and creation. 

Clark University is exclusively what is called in Europe a Philo- 
sophical Faculty, or a part of one so far as yet developed, devoted to a 
group of the pure sciences which underlie teclmology and medicine, but 
does not yet apply its work to these professional fields. These or a 
college course could be added with relatively less expense. Our 
method has brought us face to face with many new problems. Our 
efforts at solving some of these are described in the department reports 
which follow. Like all new institutions, we have not entirely escaped 
trials, but we trust we have learned their lesson, and shall be the better 
and stronger for them. Instead of dispersing our energies in university 
extensions, we have followed the opposite course of university concentra- 
tion, like the Ecole Pratique of France. Accepting the plain lesson of 
history that the best educational influences work from above downward, 
that universities create the material of culture, wliile lower institutions 
are the canals for its distribution, we have sought aid for the latter work 
by an educational sub-department and summer school. We are not like 
the Smithsonian Institute, the Naples school, the Heichsanstalt, academies 
of science, etc., devoted solely to research, but have to make our lectures 
more condensed and fewer than usual, because addressed to advanced 
men, and to devise ways of making seminary and laboratory, two of the 
noblest words in the vocabulary of higher education, more effective. We 
have tried to effect systematic exchanges with foreign institutions, — and 
our library has profited largely from this source, — and have sought by 
all the above means to aid in giving to universities and to professors the 
position due them in a time when sciences have come to underlie all the 



10 Historical Sketch. 

arts of peace and war, and when the world, in all its activities, industry 
and trade, professions, legislation, is coming to be more and more con- 
trolled by experts, thus trained to the frontier of their specialties. 

The degree of Doctor of Philosophy has been conferred upon can- 
didates, whose names, together with the dates of their final examinations 
and the subjects of their dissertations, are given later in this volume. 

Other historical facts are given in the President's Address at the 
Decennial Celebration. 



REQUIREMENTS FOR THE DEGREE OF DOCTOR OF 
PHILOSOPHY. 

At least two years, and in most cases three years, of graduate work 
will be necessary for this degree. Examinations for it, however, may 
be taken at any time during the academic year when, in the judgment 
of the University authorities, the candidate is prepared. A prearranged 
period of serious work at the University itself is indispensable. 

For this degree the fu'st requirement is a dissertation upon an 
approved subject, to which it must be an original contribution of value. 
To this capital importance is attached. It must be reported on in 
writing by the chief instructor before the examination, printed at the 
expense of the candidate, and at least one hundred copies given to 
the University. In case, however, of dissertations of very unusual 
length, or containing very expensive plates, the Faculty shall have 
power, at the request of the candidate, to reduce this number of presen- 
tation copies to fifty. 

Such formal or informal tests as the Faculty shall determine, shall 
mark the acceptance of each student or fellow as a candidate for this 
degree. One object of this preliminary test shall be to insure a good 
reading knowledge of French and German. Such formal candidature 
shall precede by at least one academic year the examination itself. 
(See special rules below.) 

The fee for the doctor's degree is $25, and in every case it mxist 
be paid and the presentation copies of the dissertation must be in the 
hands of the Librarian before the diploma is given. In exceptional 
cases, however, and by special action of the Faculty, the ceremony 
of promotion may precede the presentation of the printed copies of 



Historical Sketch. 11 

the dissertation. The latter, however, must always precede the actual 
presentation of the diploma. 

An oral but not a written examination is required upon at least 
one minor subject in addition to the major, before an examination 
jury composed of at least four members, including the head of the 
department and the President of the University, who is authorized 
to invite any person from within or without the University to be 
present and to ask questions. The jury shall report the results of 
the examination to the Faculty, which, if it is also satisfied, may 
recommend the candidate for the degree. 

For the bestowal of this degree, the approbation of the Board of 
Trustees must in each case be obtained. They desire that the standard 
of requirements for it be kept the highest practicable, that it be reserved 
for men of superior ability and attainment only, and that its value 
here be never suffered to depreciate. 

It is to the needs of these students that the lectures, seminaries, 
laboratories, collections of books, apparatus, etc., are specially shaped, 
and no pains will be spared to afford them every needed stimulus 
and opportunity. It is for them that the Fellowships and Scholarships 
are primarily intended, although any of these honors may be awarded 
to others. 

SPECIAL BULES. 

I. Residence. — No candidate shaU receive the degree of Doctor of 
Philosophy without at least one year's previous residence. 

II. Candidature for the Doctors Degree. — Every applicant for the 
doctor's degree shaU fill out before October 15th the regular appli- 
cation blank provided at the office. This schedule shall be submitted 
to the head of the department and the instructor in the major subject. 
Before affixing their signatures they shall satisfy themselves, in such 
manner as they may desire, as to the fitness of the applicant. 

III. When countersigned, this schedule shaU be filed with the 
President, who will appoint an examiner to serve with a representative 
of the major subject as a committee to determine the proficiency of 
the applicant in French and German. 

IV. In case of a favorable report by this committee the applicant 
shall be a regular candidate for the degree. 

V. Candidates complying with all preliminary conditions, including 



12 Historical Sketch. 

the examinations in French and German, before November 1st, will 
be allowed to proceed to the doctor's examination at any time between 
May 15th following and the end of the academic year. 

VI. Dissertation. — The dissertation must be presented to the in- 
structor under whose direction it was before written, and reported upon 
by him before the final examination. In every case the dissertation shall 
be laid before the jury of examination, at the time of examination, in form 
suitable for publication. This provision shall not, however, preclude the 
making of such minor changes later as the chief instructor may approve. 

VII. The dissertation shall be printed at the expense of the can- 
didate, and the reqiiired copies deposited with the Librarian within 
one calendar year from the 1st of October following the examination. 
The candidate alone will be held responsible for the fulfilment of these 
conditions. 

VIII. The favorable report of the chief instructor, filed in writing 
with the Clerk of the University, shall be a sufficient imprimatur or 
authorization for printing as a dissertation. The printed copies shall 
bear upon the cover the statement of approval in the following words, 
over the name of the chief instructor : — 

A Dissertation submitted to the Faculty of Clark University, Wor- 
cester, Mass., in partial fulfilment of the requirements for the degree 
of Doctor of Philosophy, and accepted on the recommendation of 
(name of the chief instructor). 

IX. Examinations for the Doctor'' s Degree. — The examinations for 
the doctor's degree may be held at any time during the academic 
year, provided that at least one academic year has elapsed since the 
completion of the preliminaries of candidature, except in the case of 
fulfilment of these conditions between the beginning of any academic 
year and November 1st of that year, to which case Rule V. applies. 
The examinations shall be held at such hours and places as the President 
may appoint. 

X. Examinations may also be held during the regular vacations 
of the University, but for these an additional fee of five dollars to 
each examiner, and the reasonable travelling expenses of any examiners 
who are out of town, all payable in advance, will be required. 

XL All these special rules shall go into force immediately as far 
as practicable, and shall govern all applicants for degrees in the academic 
year 1899-1900, 



THE DECENNIAL CELEBRATION. 



The work of Clark University is so teclmical and special that it is 
necessarily more or less withdi-awn from popiilar interest. It has no 
commencements, and comes in very little contact with the public or the 
press in Worcester, or indeed with collegiate institutions in other parts of 
the country. This is a disadvantage so far as local or general public 
interest in its work is concerned, but the fact that it does not exercise 
many of the usual functions of a college is also a distinct advantage to its 
scientific work. The close of the tenth year of its existence presented an 
opportunity to bring before the public, in a simple way, befitting at once 
its size and its quality, a presentation of the work it has accomplished in 
the past and of its hopes and needs for the future. Early last winter the 
President began to consider plans of marking this anniversary, and, with 
the ef&cient aid of the Faculty, they gradually took definite shape. A 
personal appeal was then made to a number of public-spirited and wealthy 
citizens of Worcester, and the scheme was rendered feasible by the gen- 
erosity of the following gentlemen, who donated the sums aifixed to their 
names : — 

Mr. Stephen Salisbury, $1000 

Mr. Philip W. Moen, 600 

Mr. Thomas H. Dodge, 200 

Mr. Edward D. Thayer, Jr., 200 

Mr. Charles S. Barton, 100 

Mr. John H. Goes, 100 

Mr. Andrew H. Green, 100 

Mr. Arthur M. Stone, 100 

John 0. Marble, M.D., 60 



Mr. C. Henry Hutchins, $500 

Mr. William E. Eice, 600 

Mr. Orlando W. Norcross, 200 

Mr. Matthew J. Whittall, 150 

Mr. A. Swan Brown, 100 

Mr. Loring Goes, 100 

Mr. James Logan, 100 

Mr. Joseph H. Walker, 100 

Mr. Frederick L. Goes, 25 



Gharles L. Nichols, M.D., $25. 
13 



14 Decennial 

It was decided that the close of the tenth academic year should be 
celebrated (1) by courses of lectures delivered by distinguished foreign 
scientific men, (2) by public exercises, and (3) by an evening reception. 

A conference was then held concerning the most prominent leaders in 
Europe in branches especially cultivated at the University, and after some 
correspondence the following persons were invited to give from two to 
four lectures each : — 

Emile Picaed, Professor of Mathematics at the University of Paris. 

LuDwiG BoLTZMANN, Professor of Theoretical Physics at the University of 
Vienna. 

Angelo Mosso, Professor of Physiology and Eector of the University of Turin. 

Saijtiago RAMdN V Cajal, Professor of Histology and Eector of the Univer- 
sity of Madrid. 

August Fokel, late Professor of Psychiatry at the University of Zurich and 
Director of the Burgholzli Asylum. 

Under the direction of a committee consisting of Assistant Professor 
A. G. Webster and Professor W. E. Story, the following forms of 
invitation to the various parts of the programme were prepared: — 



Celebration. 



15 













S'i&a^t, le/Jitif. 



16 Decennial 



■a-f^ 







■c^■^' Mt-€- .AU-e-t'e4'4-tM4^-a'^ 



Cy€--yi-in' G^zz<:t€yf^yi.i^ \^^€^:iA- -OjP m^ \lt-n.^^Li-e4(Ul>^ 



C/l/i'-Oyn.'c:^^:!^ -^n^i-i^^-i/n^, j/u't^ ^^e- t-g.^n^/i, 



^^^*C^i 



^^* 






Celebration. 



17 










t&a^& 'be/fuly'. 



18 Decennial 

The invitations to the lectures were sent to such persons as were con- 
sidered to be particularly interested in the subjects in question, of whom 
over one hundred accepted. Many declinations were inevitable and 
expected, owing to the unfavorable season of the year and, perhaps in 
part, to the somewhat too short notice given. The lecturers all arrived 
in due season, and were entertained as follows : — 

Professor Emile Picard, by Professor W. E. Story. 

Professor Ludwig Boltzmann, by Assistant Professor A. G. Webster. 
Professor Angelo Mosso, by President G. Stanley Hall. 

Professor S. Eamda y Cajal, by Hon. Stephen Salisbury. 
Professor August Porel, by Dr. Adolf Meyer. 

The lectures were held in the large lecture-room on the first floor, and 
were well attended. Professors Picard and Cajal lectured in French, and 
Professors Boltzmann, Mosso, and Forel in German. Their lectiues are 
printed in full elsewhere in this voliame. 

Many social functions occurred during the week ending July 8. On 
Wednesday evening, Professor Story received informally the attendants 
on the lectures of Professors Picard and Boltzmann ; on Thursday evening 
President Hall gave a reception to all the visitors ; and on Friday after- 
noon and evening the whole company was entertained by Hon. Stephen 
Salisbury at the Quinsigamond Boat Club house. 

The second part of the celebration occurred on Monday morning, 
July 10, beginning at 10.30, in the University. The professors had 
adopted academic costume, and many distinguished guests were seated 
upon the platform. The exercises opened with prayer by the Rev. Alex- 
ander H. Vinton, Rector of All Saints' Church. 

A few extracts from congratulatory letters were read by Professor 
Story, which are printed elsewhere in this volume. Brief congratulatory 
addresses were made by President Faunce, of Brown University, repre- 
senting the New England college presidents ; and Professor Bowditch of 
the Harvard Medical School, representing the higher scientific institutions 
of the state. 

President Faunce said : — 

" I count it a very happy fact that the first occasion on which I am to 
officially speak, representing Brown University, is at this anniversary at 
Clark University. I bring you to-day greetings from an institution of the 
higher learning founded in 1764 to a university founded in 1887. It is 



Celebration. 19 

safe to say that Clark Universitj^ has clone more to widen the confines of 
human knowledge than any other American college in one hundred and 
fifty years. 

" When Professor J. P. Cooke, of Harvard, applied to the Faculty for 
chemicals and apparatus for experiment, he was told he must secure the 
materials at his own expense, and that he must be responsible for any 
explosions or damage in consequence of his experiments. From that day 
to this is a long step. Our method of applying nature has been trans- 
formed within a very few years. The distance between Acliilles' coach 
and the English stage-coach is not the same as that between the stage- 
coach and the Empire State express. The difference between the Phoeni- 
cian galleys and the Bon Homme Richard is not the difference between 
the Bon ITomme Richard and the modern battleship. The little world of 
Shakespeare has become one vast luiiverse of learning, and the field has 
broadened almost infinitely in all directions, and the goal is the far-off 
divine event toward which the whole creation moves. 

" In this movement of scholarship the enrichment of one institution 
is the enrichment of all, the enfeeblement of one is the enfeeblement of 
all. You have received at this celebration, almost Spartan-like in its sim- 
plicity, the congratulations not alone of America, but of Berlin and 
Munich and Vienna, because your advance and success is the advance 
of all. Only geographically and superficiallj^ are the leaders of modern 
scholarship divided, and so we congratulate you, not because you have 
duplicated existing plants, but that you have filled a place hitherto 
unfilled and have broken new ground. 

" Here among all the institutions of learning you have not detracted 
from the success of other institutions, you have placed fresh laurels on the 
heads of each. All of us feel a warm interest and admiration for this 
University because of the simple, quiet, and noble work done within these 
walls." 

Dr. Bowditch said that he was quite unprepared to say much, and he 
thought it just as well, for he belonged, in the words of Dr. Holmes, to 
the "silent profession." He paid a tribute to the felicitous speech of 
Dr. Faunce, which left him little to say. Dr. Bowditch spoke of the 
great work in scientific research being conducted by the institution, and, 
after some wishes for its prosperity, congratulated the youngest college 
in the name of the oldest college in Massachusetts. 



20 Decennial 

Then followed the address by President Hall, printed elsewhere in this 
volume. 

The honorary degree of Doctoe op Laws, honoris causd, was then con- 
ferred, for the first time, upon the five foreign professors in the following 
terms : — 

" By virtue of the authority vested by the Commonwealth of Massachu- 
setts in the Board of Trustees of Clark University, and by them dele- 
gated to me, I now create you Doctor of Laws, honoris causd, and by this 
token [presenting diploma] invest you with all the dignities thereunto 
appertaining." Brief responses were made, of which translations follow. 

LUDWIG BOLTZMANN. 

The problem of science is a twofold one : first, to advance our knowledge 
of nature independently of any practical application ; and second, to make 
practical applications of the knowledge gained. Although to a superficial 
observer it may seem that the latter is of greater importance, the develop- 
ment of humanity has shown in the most convincing way that the first 
kind of activity is not only of paramount importance, but that the leading 
role belongs to it. In fact, it is only thanks to the pioneers of science 
who, laying aside all practical applications, penetrate deeper and deeper 
into the essence and arrangement of the forces of nature, that humanity 
has obtained that sway over the laws of nature which makes possible the 
present practical achievements. 

The German universities have devoted themselves at all times to the 
nurture of pure science apart from its practical applications, although but 
one of the four university faculties is consecrated to it, and that one not 
entirely. It must be considered as a good omen, therefore, that here in 
America, which is usually taken to be the land of practical men, the ideal 
of a place entirely consecrated to the service of pure science, unattainable 
in Germany, has found its realization, so that I, who am body and soul a 
German professor, deem it a great honor to have conferred on me in this 
place, the greatest distinction which the University can grant. While 
desiring Clark University to flourish and thrive in the intimate conviction 
that the whole scientific world is interested in her prosperity, I express 
my thanks to the President and all its members for the high honor 
bestowed upon me to-day. 



Celebration. 21 



Santiago Ramon y Cajal. 



I OFFER my most cordial thanks to Clark University for the honorable 
distinction she has bestowed upon me in spite of my small deserts by 
granting to me the degree of doctor of laws by this learned body, the 
remembrance of which will never fade from my memory. This honor 
I deem to be the prize of the greatest value which my modest researches 
have procured for me, and the one which will encourage me most in my 
worship of the laboratory tasks and of the study of natiu-e. This 
honorary distinction, as well as the invitation which Clark University 
condescended to make me to take part in the conferences for solemnizing 
the tenth anniversary of its foundation, shows once more that the men of 
science know of no frontiers, and that they form a universal family, whose 
solidarity and fellow-feeling place them high above the wrangle of mate- 
rial interests and selfish struggles of nationalities. 

It was truly a happy idea to create in America a university of higher 
studies, devoted not only to the labor of teaching, but also very especially 
to giving impulse to pure science. It has been said many times, but never 
enough, that there is no lasting industrial progress if it is not connected, 
as a brook with its source, with the creation of original science. 

No matter how great the practical genius of a nation, it is impossible 
for it to preserve its political, commercial, and industrial hegemony, unless 
it comes out intellectually superior to other nations, miless it attends with 
equal care to the laboratory and to the mill, to the ideas as well as to the 
inventions, to the philosophy and to the science wliich guide as well as to 
the art which carries out. 

This happy alliance between theory and practice is what places Ger- 
many to-day at the head of civilization. It would be easy to adduce nimi- 
berless examples of the supremacy which industry, founded on science, 
holds over empirical industry created at haphazard according to the 
inventive character of each nation. I will quote only two — the chemical 
industry of the aniline dyes created chiefly in Germany, which assures 
to that nation an immense wealth ; and the optical industry representing 
all kinds of apparatus (microscopes, photograpliical and astronomical 
object-glasses) which sprung up tmder the inspiration of the great 
mathematicians. Abbe, Rudolph, Goertz, and others, and which by its 
manifest superiority over that of other nations procures to Prussia a 
monopoly which makes the whole world her tributary. 



22 Decennial 

That is the right way, the only one which leads to glory, wealth, 
and power. I trust that the creation of Clark University may give the 
signal for founding in America other similar institutions embracing a still 
larger number of branches of science, and having as their primary object 
the wresting of secrets from nature, supplying industry and arts with 
principles and facts capable of fruitful applications, forming the research 
spirit of the new generation, freeing it from the clogs of routine and 
imitation, and finally forming the foundation of a splendid civilization 
superior in groundwork, as well as in form, to that of the European 
nations. 

August Foeel. 

I THANK you heartily for the great honor you have bestowed upon me 
by conferring upon me the degree of doctor of laws, honoris caiisd, of 
Clark University. But I accept this honor less in my own person than 
as a representative of Switzerland at your celebration — in the name of 
my little fatherland. Although nowadays the Swiss Federation disap- 
pears beside the powerful republic of the United States, yet she prides 
herself still on being the little old mother of democracy, which has fought 
for her free rights for centuries, and has maintained them up to the 
present day. I offer my heartiest congratulations for the brilliant success 
which Clark University has achieved during the short time of its exis- 
tence in the high domains of philosophy, pedagogy, and of many a scientific 
foundation of social questions. But we must also offer our heartiest 
thanks and congratulations for the generous and magnificent gifts of 
American citizens for the furtherance of scientific and social progress. 
Allow me to add a wish. Let Clark University continue to pursue — 
vmder the successful guidance of her excellent President, Professor G. 
Stanley Hall — her researches in the regions of psychology and pedagogy 
together with those on the brain and its life, and thus to further the 
investigation and the building up of truth in the teeth of all prejudices. 
Let her help to bury the old roads of barren metaphysical dogmas and 
speculations, and thus develop in its entirety the only fruitful ethically 
built-up progressive method of scientific investigation in these domains, 
as a blessing to our posterity and for the good of a better and happier 
humanity. 



Celebration. 23 

Angelo Mosso. 

I OFFER my thants to Clark University for the honor bestowed upon 
me. I shall carry with me to Italy a happy remembrance of the many 
proofs of sympathy and friendship which I have received in the Uni- 
versity and the city of Worcester. It is not only the expression of my 
gratitude that I offer you, but also my great admiration for all that I 
saw in your University, and especially the development in experimental 
psychology under the happy impulse which the President has given to 
this branch of science. It is not only on my own account that I offer 
you my thanks, it is also because, on my return to Italy, I hope to found 
in the University of Turin a school of experimental psychology. 

Emile Picaed. 

I OFFER my heartiest thanks to the President and Professors of Clark 
University for the degree just conferred upon me. I have been also greatly 
touched by the honor you bestowed upon me by inviting me to give a few 
lectures during tins academic celebration. Your desire was thus to bear 
witness to your sympathy with men of science in France. We follow on 
our side, in France, with great interest the American scientific movement, 
and we rejoice in seeing closer relations established between our universi- 
ties and those of this country. Science treads its ascending march on 
different roads, and research work requires to-day the most varied apti- 
tudes. The initiative and the energy which are prevalent in this country 
will not be wanting in occasions for displaying themselves, and, in aU 
branches of studies, the American scientists will be able to erect some- 
thing equivalent to those large telescopes by means of which your astrono- 
mers have made such beautiful discoveries. It is in the universities which, 
like this one, are devoted to research, that the scientific movement is bound 
to have its origin. From everything I have seen and heard for the last 
few days, I am certain that the eminent professors of this University 
devote themselves with success to this noble task, and I beg to offer my 
most sincere wishes for the continuance of the brilliant development of 
Clark University. 

The exercises concluded with prayer by Dr. Vinton. 

The closing exercise of the decennial was a reception which was 
attended by between five hundred and six hundred ladies and gentlemen 



24 Decennial Celebration. 

of Worcester. The arrangements had been made under the direction of 
Assistant Professor Henry Taber and Professor William E. Story. The 
large lecture-room and corridors were decorated with festoons of green 
and white, the flags of the United States and of the native countries of 
the foreign guests, and with potted plants. A collation was served in the 
library, and many pieces of apparatus were exhibited in operation in the 
physical and psychological laboratories. 

The following persons received : President G. Stanley Hall, Miss 
Florence E. Smith of Newton Centre, Mass., Mrs. A. W. Beals of Stam- 
ford, Conn., Hon. Stephen Salisbury, Dr. Edward Cowles, Miss Gage, 
Professor and Mrs. William E. Story, Assistant Professor and Mrs. Arthur 
G. Webster, Assistant Professor and Mrs. Clifton F. Hodge, Assistant 
Professor Edmund C. Sanford, Miss Sanford, Assistant Professor Henry 
Taber, Dr. and Mrs. A. F. Chamberlain, the foreign lecturers, Senora 
Ramon y Cajal, and Frau Boltzmann. 

The press of Worcester gave very full and detailed accounts of all 
that transpired during the week except the scientific lectures, all of which 
were in foreign languages and upon very technical subjects. 

The following original documents have been bound and filed in the 
University library : — 

(1) The congratulatory letters, telegrams, etc. 

(2) The correspondence with the foreign lecturers, and the letters of 
acceptance and declination from American professors. 

(3) The letters of acceptance and declination to the reception in the 
evening. 

The weather was somewhat warm during the fil'st few days, but was 
clear and cool on Saturday, Sunday, and Monday. The hospitality of 
Worcester people was all that could be desired. 



CONGEATULATIONS. 



The following extracts are taken from many hundred congratulatory- 
letters, personal, official, and from institutions and educators of all grades 
and many lands. 

Congratulations on the conclusion of the University's first decade, and best 
wishes for the successful continuance of the work it has undertaken. 

William McKinlet, Washington, D.C., 
President of the United States. 

The attraction will be strong to all who are interested in the great subjects 
which these distinguished men will discuss, or in intellectual eminence for its 
own sake. Your occasion will be the most distinguished gathering that will 
occur in all New England this summer. . . . 

The high plane of the work done at Clark University, the only institution 
in our country exclusively devoted to original research and the instruction of 
advanced investigators, so far as I am aware, is well kuo^vn to all who have 
followed the course of the University. Modestly, and without ostentation, it 
has pursued its noble ideals. If, \mder your able direction, its means were more 
extensive, the University would, doubtless, become the centre of a still larger 
circle of influence in the training of men for the prosecution of original research 
and the conduct of similar work in other institutions. I trust that your own 
large plans and those of the founder of the University may enjoy a complete 
realization, and that its future may be crowned with the high success which so 
great an enterprise rightly deserves. 

Felicitating the honored founder, yourself, the trustees, and your colleagues 
in the faculty upon the great occasion you are soon to celebrate, 

David J. Hill, Washington, D.C., 
Assistant Secretary of State. 

It is one of the chief regrets of my life that I cannot attend the celebration 
of Clark University. Be assured that no reason personal to myself has pre- 
vented my attendance. I have seriously considered the question of crossing the 
Atlantic for the purpose, and coming back here immediately afterward. But 
that seems impracticable. 

25 



26 Extracts from 

We have to congratulate the University upon ten years of success. It was 
not to be expected that an institution whose aim is to lift the university educa- 
tion, not only of this country, but of the world, to a higher plane, and to break 
out a new and untrodden path, should command popularity in the beginning, or 
that its success should at once be recognized by the general public. But we 
have no cause for regret or for discouragement. Teachers whom we have edu- 
cated are found in institutions of the first class in all parts of the country, and 
all parts of the world have sent representatives to receive our instruction. This 
is largely due to the wise and far-sighted intelligence of the founder, and, next, 
to your own constant and self-sacrificing labors. 

There have been times during these ten years when we have been tempted 
to think that the people of Worcester have been cold, and have been lacking in 
the liberality which we had hoped from them when we started. But in looking 
at the history of other institutions which are now useful and flourishing, it will 
be seen that they had in the beginning a like experience. I remember well a 
time when it almost seemed impossible to get the people of Worcester to endow 
a public library. But the hour came and the man came, and our public library 
is now munificently endowed and is a model of library administration. The 
Polytechnic Institute had its day of small things. But the liberality of two 
citizens of Worcester of the same name and race, whose two lives seem almost 
like the prolonged life of one individual, came to its aid, and it is now doing its 
work with large endowments, and its scheme has been copied by other institu- 
tions all over the country. I do not for a moment doubt that the time will come 
when our endowments will enable us to maintain in the entire circle of univer- 
sity education the position which we have taken and hold with regard to a few 
subjects. Already an eloquent orator, formerly head of the National Catholic 
University at Washington, has referred to Clark as " that little institution in 
Worcester which has added a new story to university education, and 

' Whioli allures to brighter worlds and leads the way.' " 

An eminent professor of science from the English Cambridge declared at a 
meeting in the British Association, in the presence of famous scholars from all 
parts of the world, that there is one thing that England envies America, and 
that is Clark University. 

There is nothing except the country itself which ought to inspire a deeper 
devotion in its children than a university. As time goes on this feeling, made 
up of love and gratitude, will be found in fullest measure among the alumni of 
Clark. As they go out to reap the harvests of success in life, they will repay 
to their alma mater, in their own way, the great debt they owe her. When that 
time comes I have no fear that her endowments will not be ample to accomplish 
the work she has undertaken. In the meantime those of us to whom the con- 
fidence of the founder has committed a share in her administration must renew 
our own vows of fidelity to her service. 

Among the many public honors which the undeserved kindness of my fellow- 



Congratulatory Letters. 27 

citizens has bestowed upon me, I count none higher than my selection as one of 
the first board of trustees of this institution. I trust that your celebration will 
be full of delight for those who gather there, that they will look forward with 
bright hopes to the future, and that an immortality of fame and usefulness may 
await the institution which now celebrates its tenth birthday. 

Geokge F. Hoae, 

United States Senator. 

I learn from your formal letters of invitation that you are to celebrate the 
close of the first decade of Clark University. It is one of the most wonderful 
careers to be chronicled in the history of American education. I congratulate 
you on your eminent success in conducting your University in so efficient a 
manner toward the improvement and elevation of pedagogy in the United 
States. Your movement is all the more valuable because it challenges the aims 
and purposes of the present existing education. It is an elementary force in 
making the American teachers circumsfiect and reflective, and causing them to 
seek deeper principles on which to ground their practice and on which to im- 
prove it. Hoping that there will be a long series of equally useful decades in 
the history of Clark University and in your own successful directorship of that 

institution, 

W. T. Harris, Washington, B.C., 
Commissioner of Education. 

I cannot refrain from offering my congratulations to the President, Trustees, 
and Faculty for securing the services of such distinguished lecturers, as well as 
for the marked success that has attended Clark University during the first 

decade of its existence. 

Willis L. Moore, Washington, D.C., 
Chief of Weather Bureau. 

I must add my profound appreciation of the great work for the highest 
science that is being accomplished by you. The solid knowledge that consti- 
tutes " Science " is a rather slow growth — it can only advance in proportion as 
man frees himself from ancient errors and evolves higher powers of observation 
and reason. The fine work done at Clark, the excellent memoirs published by 
its professors, and now these attractive lectures, give us all the assurance that 
your labors for the highest attainments in the study and teaching of science 

will be abundantly rewarded. 

Cleveland Abbe, Washington, D.C., 
Weather Bureau. 

Congratidating you on the successful rounding out of the first decade of the 

University, and with best wishes for the success of the institution in the 

future, 

' W. J. McGeb, Washington, D.C., 

Smithsonian Institution. 



28 Extracts from 

I send you most cordial greetings on the interesting occasion, and hope the 
future of Clark will be as successful as the past, and that your plans for scien- 
tific research may be realized in the fullest degree. 

Cakroll D. Weight, Washington, D.C., 
Commissioner of Labor. 

One may well be envious of the gratification that the generous founder of 
Clark University must feel at the world-wide recognition of its achievements 
during the very first decade of its existence. 

To have established a just claim upon the regard of foremost men associ- 
ated with educational establishments in this country and in Europe is of great 
significance. 

The work that the University has done and is doing will continue to attract 
to its halls those rare geniuses who, impressed with the transcendent importance 
of the science of Pedagogy, of Physiology and Psychology, seek with unfailing 
diligence to penetrate their inmost depth. This work can scarcely fail to exer- 
cise a beneficial influence upon the schools of the country, and become a distin- 
guished attraction to the city which is fortunately the home of the University, 
whose citizens will give it welcome and encouragement and markedly recognize 
the munificence of its founder, as well as the labors of those who have in so 
brief a time established it among the foremost seats of learning. 

Andrew H. Green, 

214 Broadway, New York City. 

As I shall not be able to be present during the exercises on Monday, July 10, 
celebrating the completion of the tenth academic year of Clark University, I 
desire to express in writing my feelings of sympathy and my strong desire for 
the success of the University, and also to extend to you and your co-workers my 
sincere congratulations on this auspicious occasion. 

It is probably true that the initiative step of the institution was not fully 
understood or appreciated by the public, but during the past ten years it has, 
under your able and judicious direction, steadily pursued a course well calcu- 
lated to win its way to public confidence and to an abiding position among 
the most eminent and distinguished institutions of learning in the civilized 
world. 

The entire exercises attending the celebration are calculated to draw aside 
the mystic veil, and when the occasion shall have been numbered among past 
events, the general public will be led to see and know Clark University in the 
future as it has been seen and known in the past by distinguished foreign scien- 
tists and educators. 

Yes, rest assured. President Hall, that before the last hour of the present 
century has been struck by the unerring and mighty hand of time, Clark Uni- 
versity, the far-seeing, noble, and generous foimder, together with the Univer- 
sity's learned and distinguished first president, will have been crowned by 



Congratulatory Letters. 29 

truth and justice with the laurel wreath of victory, exalted merit, and uni- 
versal appreciation. 

Thomas H. Dodge, Esq., 
Worcester. 

James Brice begs to be permitted to offer his congratulations upon that 
occasion. 

Will you please convey to them my best wishes for the continued prosperity 
of Clark University. It has a high mission ; for gathering in new knowledge 
is a much nobler task than distributing that wMch is known, useful as the latter 
may be. 

I feel confident that when your present age is lengthened tenfold and 
your successors celebrate the centenary, they an^II hold up a great record of 
influence for good in the States and in the world. 

Professok Michael Fostek, 

University of Cambridge, England. 

Though thus tardily, it is none the less heartily, that I congratulate you and 
your colleagues and fellow-citizens in this celebration — and this not simply on 
reaching your first natui-al period of retrospect, but on the worthy manner of the 
celebration also. You are certainly setting forth a feast of rare and varied 
intellectual fare, and thereby also giving a great lesson to us in the Old World 
of that return to the international unity of universities, which it is fitting that 
you in America should lead. Again accept these my best wishes for the cele- 
bration, with heart}' congratulations upon your vigorous and productive youth 
— with confident hope also of your yet more productive matui'ity. 

Professor T. W. Geddes, 

University of Edinburgh, Scotland. 

Arthur Bienatme (Toulon, France) addresses to the President his most 
sincere prayers for the prosperity of the Universitj''. 

I address my wishes for the brilliant future of your University. 

Professor Alfred Binbt, 
Paris, France. 

I find it unfortunately impossible to avail myself of your invitation, for I 
certainly would have desired to enter into personal relations with men who join 
to their high science a largeness of view seldom to be met with. 

Professor Jules Tannery, 
Paris, France. 



30 Extracts from 

My congratulations on the completion of the tenth academic year of the Uni- 
versity, with my best wishes for its increase and prosperity. 

Peofessok Adolf Baginskt, 

University of Berlin, Germany. 

I avail myself of this occasion to express my heartiest wishes for the further 
prosperity of your University. I rejoice at the admirable way in which you are 
to celebrate the foundation of your institution, thereby showing that it is to 
remain what it has hitherto been: the home of scientific investigation and 

culture. 

Phofessor Max Dessoie, 
Berlin, Germany. 

I express my heartiest wishes for the prosperity of your University, whose 
scientific activity has so soon won for it a high place among the universities of 

your country. 

Pkofessor Benno Erdmann, 
Bonn, Germany. 

In your effort to unite the nations under the banner of unselfish science, 
accept my most cordial congratulations and wishes for prosperity. 

Pkofessoe Paul Flechsig, 

University of Leipzig, Germany. 

I request you to receive my sincerest congratulations to this academical 
solemnity, and the expression of my hope, that your institution, highly ad- 
vanced through many diificulties and sacrifices, may enjoy the most splendid 
prosperity for many secula. 

Peofessok Eknst Haeckel, 

University of Jena, Germany. 

I send to you and Clark University best wishes for success. 

Professor Felix Klein, 

University of Gottingen, Germany. 

Permit me to express my warmest wishes for the future prosperity of your 
University, which, called to life ten years ago, has already won such deserved 
success. 

Professor Kuhne, 

University of Heidelberg, Germany. 

Accept my heartiest congratulations on your approaching celebration, and 
may it be the dawn of a still more momentous era than the preceding one has 
already been. 

Professor Oswald Kulpe, 

University of Wurzburg, Germany. 



Congratulatory Letters. 31 

May the following decennium of Clark University be prosperous in its 
development and rich in scientific results. 

PkOFESSOR LlNDEJIAKN, 

University of Munche7i, Germany. 

I express my good wishes on the occasion of the celebration. 

Pkofessor Max Noethek, 

University of Erlangen, Germany. 

I do not want to let slip the opportunity of expressing my best wishes for 
the University which has done so much for science, and is spoken of, particu- 
larly in Germany, with the highest respect and esteem. 

Pkofessor Kanke, 

University of Munchen, Germany. 

With the best wishes for the growth and success of your University, 

Professor W. Rein, 

University of Jena, Germany. 

I offer my best wishes for the welfare and progress of the University. 

Professor C. Eunge, 

Hannover, Germany. 

Permit me to send my heartiest congratulations on this celebration. Under 
yoiu- guidance Clark University has, in the ten years of its existence, already 
won for itself a high reputation in the whole scientific world. May the second 
decennium continue like the first to advance and increase science, and may it 
be granted to you, Mr. President, for many years to come to be the standard- 
bearer of the scientific labors of Clark University. 

Professor Hermann Schiller, 

University of Giessen, Germany. 

Wishing the University further prosperity and progress. 

Professor P. Schdr, 

Karlsruhe, Germany. 

I remember my sojourn in America and the kind reception which I met 
with in Worcester.' I should rejoice to have the opportunity to renew the 
hospitality shown me by yourself and by your colleagues. 

Professor E. Studt, 

University of Greifswald, Germany. 

May the young University, which has already developed so auspiciously, 
continue according to the old saying : Vivat, floreat, crescat ! 

Professor Waldeter, 

University of Berlin, Germany. 



32 Extracts from 

I should have also been especially desirous of bringing to you my own 
recognition of what has hitherto been accomplished and my cordial wishes for 
the future. I follow with great interest particularly the psychological works 
which proceed from your University and are published in the American Journal 
of Psychology. I have always received from them the impression that the 
psychological and pedagogical departments of your University belonged to the 
most important institutions of their kind. 

May Clark University complete the second decennium of its existence 
with like, and where possible, increasing glory! 

Pkopessor W. Wundt, 

University of Leipzig, Germany. 

Accept my warmest wishes for the development of the University. 

Professor Ed. Wetr, 

University of Prague, Austria. 

I feel a great pleasure in congratulating your Clark University on the cele- 
bration of the festival ; and allow me to express the hope that your University 
may extend its activity with every year to the honor of its President, its 

Trustees, and all its Members. 

Professor S. E. Henschen, 

University of Upsala, Sweden. 

I beg you to receive my cordial congratulations on the occasion of the 

beautiful decennium which your University has completed. I hope that this 

seat of learning shall have a future correspondingly to the excellent manner in 

which it has begun its life. 

Professor H. Hoffding, 

University of Copenhagen, Denmark. 

I beg to present my sincere congratulations upon the erection of a scientific 
centre, the decennium of which you are to celebrate in so fitting a manner. 

Professor Zeuthen, 

University of Copenhagen, Denmark. 

I send you the best wishes for the success of your celebrated University, 

Professor Vito Volterra, 

University of Turin, Italy. 

Eternal prosperity to the vigorous propagator of light. 

Professor Stephanos, 

University of Athens, Greece. 

De. Wesley Mills (McGill University, Montreal, Canada) wishes the Uni- 
versity every success in the future. 



Congratulatory Letters. 33 

With best wishes for the continued prosperity of Clark University, 

Pkofessoe J. Squair, 

University of Toronto, Canada. 

President Angell (University of Michigan) congratulates them on the 
useful work which the University has already accomplished. 

With hearty congratulations for what you have already achieved as President 
of Clark University, and in full assurance of a great future before you, 

Henry Barnard, Hartford, Conn., 

Ux-Tf. S. Commissioner of Education. 

William W. Bikdsall (President Swarthmore College) desires to extend 
congratulations upon the completion of the tenth year of Clark University. 

I congratulate you most heartily on the splendid work which Clark Uni- 
versity has accomplished during the ten years of its existence. Nothing in 
our educational work has reflected greater honor upon the American system 
than the high ideals so successfully maintained at Clark University. 

President John E. Bradley, 
Illinois College. 

Good wishes to the University in all its undertakings, and congratulations to 
President, Trustees, and Faculty upon the completion of ten years of distin- 
guished usefulness. Professor C. L. Bristol, 

Keio York University. 

My deepest wish is that Clark may do as much more for the advancement of 

science and the deepening of the true university spirit iu the next decennium 

as it has in the one now closing. 

Professor Edtvard F. Buckner, 

Teachers'" College, New York City. 

I beg leave to extend to you my most sincere congratulations on the work 
that Clark University has accomplished under your guidance, since the time of 
its founding, ten years ago. 

As a Fellow of the University, I enjoyed opportunities for work that other 
institutions could not afford, and I found your efforts to provide books, instru- 
ments, and material as effectual as they were untiring. 

As a Graduate I have found inspiration in your zeal for the furtherance of 
all that can advance education and science. 

I have followed the development of the University with pride. The first 
high ideals have not been lowered, and Clark remains, as it was at its founda- 
tion, a University for Universities. 

Professor H. C. Bumpus, 
Brown University. 



34 Extracts from 

No undertaking nor movement lias made so clear and definite impress upon 
the educational thought of America nor established guiding lines of control 
so distinctly in pedagogical and psychological progress as the suggestions and 
tendencies which have emanated from Clark University. Though the institu- 
tion is yet in its infancy, though the students in point of numbers have been 
limited, yet its influence has penetrated every state in the Union, has entered 
practically every educational institution of the land, from university to kinder- 
garten, and has quickened the spirit of educational conferences, from those of 
national repute to those of the little teachers' meetings of the village school. 

Granting the truth of the educational view for which Clark University 
stands, and allowing for the singularly forceful methods of instruction by the 
President and Faculty within the institution, and the energy with which its 
mission has been prosecuted, it is nevertheless still a marvel that its influence 
should have become, in this brief space, so widespread and vigorous. The facts 
which stand prove the wisdom of the plan of an iastitution which should be 
exclusively graduate, selecting as its students a limited number of mature 
thinkers who should be inspired by the power which ever comes from the con- 
tact with original investigation and a faculty of original investigators. 

Fkedekick Burk, President State Normal School, San Francisco, and 

President Clark University Alumni Association of California. 

I send my best wishes for the success of the anniversary exercises and for 
the continued and enlarged prosperity of the University. 

President Nathaniel Butler, 
Colby University. 

Kindly accept my congratulations upon the completion of your tenth aca- 
demic year. 

Professok R. H. Chittenden, 

Director Sheffield Scientific School. 

I desire to congratulate the Faculty of the University on the great work 
accomplished within a comparatively short period. 

Brother Chrtsostom, 

Manhattan College. 

We rejoice with your many friends in the successful rounding out of Clark 
University's first decade. It is a consolation to the generous benefactor that 
the world recognizes the merit of the Institution, which his munificence estab- 
lished and maintains. Coming into existence the same year, holding similar 
views as to the place of graduate work, having the highest ideals of university 
endeavor, striving earnestly to realize them in spite of all difficulty, our two 
Universities have always felt strong attachments for one another, and a more 
than ordinary interest in one another's success. The Catholic University ten- 



Congratulatory Letters. 35 

ders you its most cordial greeting on this the day of your rejoicing. It bids me 
extend to you and through you to the University its most sincere wishes for 
still higher and greater success in its chosen fields. 

Thos. J. CoNATT, Washington, D. C, 
Rector Catholic University. 

With many congratulations on the past ten years' work of the University, 

Professok Charles R. Cross, 

Massachusetts Institute of Technology. 

Peofessoe C. B. Davenport (Harvard University) desires to express his 
appreciation of the brilliant example of research as a primary university func- 
tion which Clark University has for a decade set. 

The University and all connected with it are to be congratulated. 

Professor Elleky W. Davis, 
University of Nehraska. 

I desire to express my appreciation of the splendid work done by Clark 

University during these ten years. 

Professor Nathaniel P. Davis, 

Brown University- 

I must content myself with rejoicing over the unique intellectual enterprise 
you are carrying out. I may not be informed regarding such matters, but it 
seems to me you have accomplished a sort of scientific coup cl'dtat in getting 
such a group of scholars to come to America upon the occasion of your anniver- 
sary. As a disciple of Clark University, and an admirer of everything it stands 
for, I take pride in the impression that must necessarily be made upon Ameri- 
can scholarship by the visit of such men. I congratulate all of you, and hope 
that everything you desire in connection with the series of lectures may be 

realized. ^ 

Professor George E. Dawson, 

Bible Normal College, Springfield, Mass. 

President Drown of Lehigh University begs for his colleagues and for 
himself, to offer his hearty congratulations to the President, Trustees, and 
Faculty of Clark University on the completion of a decade of usefulness in 
the higher education, marked by distinguished services in many lines of 
original research. 

Permit me to express my admiration of the work you have done and are 

doing. 

Professor William P. Dubfee, 

Hobart College. 



36 Extracts from 

Let me assure you that we are all grateful for what Clark University is do- 
ing for sound education in this country, and I can only hope that you may have 
many successful years in the development of the work which you are doiag. 

S. T. Button, Brookline, Mass., 

Superintendent of Schools. 

In the opinion of many who have studied there, the peculiar advantage of 
Clark University is mainly attributable to the close and personal relations 
between professors and students under which the work is conducted. The 
formal lecture delivered to a body of men in the class-room has but little of the 
stimulative force imparted by a conversational discussion with the man alone in 
the lecturer's private study, and too great praise can hardly be given to the 
members of the faculty of Clark for their constant and generous sacrifice of time 
to this most helpful method of instruction. The frequent assignment through- 
out the course of problems involving research leads to the best of training for 
the later performance of original work, and the presentation in the lecture-room 
of the results thus obtained gives experience in the work of the lecturer. In 
perhaps no other institution are these methods of the personal conference and 
the " colloquium " so constantly applied ; no doubt such methods are impossible 
in most larger universities at present ; and one can hardly imagine such a course 
followed with more kindness and devotion at any time than is now the case at 

Clark. 

Professor Frederick C. Ferry, 
Williams College. 

I take this means of expressing my interest in the noble success of the 
University, and of wishing it continuance and increase. 

Rabbi Charles Fleischer, 
Boston, Mass. 

Congratulating you and the University upon these years of achievement, 

Alice C. Fletcher, 

Washington, D.C. 

I rejoice in the prosperity of your institution because it is one which sends 
forth its light, not only for the few, but for the many. 

President Wm. Goodell Frost, 
Berea College. 

Though my stay with you was short, yet it meant the inspiration that took 
me abroad and pushed me on to undertake important work. 

Professor John P. Fruit, 

William Jewell College. 



Congratulatory Letters. 37 

The Johns Hopkins University sends its cordial greetings to the President, 
the Trustees, and the Faculty of Clark University, on the completion of its first 
decennium, with congratulations upon its successful maintenance of high ideals, 
and with best wishes for its continued prosperity and power. 

President Daniel C. Gilman. 

I must add my congratulations on the success of your work, and my good 
wishes for its continuance on even a larger scale. 

Professor George L. Goodale, 
Harvard University. 

Every educator especially owes a debt of gratitude to Clark for the fearless 
work it has done in breaking down blind prejudice and advancing the truth. 

Professor John Y. Graham, 

University of Alabama. 

Yon have certainly arranged a most dignified and impressive series of 
lectures — wholly congruous with the work which you have been doing during 
the decade. 

Professor Edward H. Griffin, 
Johns Hopkins University. 

You will please accept the assurance that I am very glad indeed that your 
institution, which has already done so much for the cause of progressive educa- 
tion, has thus shown its vitality and power of endurance. No doubt these ten 
years have meant much struggle and anxiety on the part of those whose heart 
was in the work. Others may be able to express their appreciation of this work 
with greater eloquence, but none can be more sincere and thankful than I am. 
Truly, if there is such a thing as a science of education in this country now, 
Clark University . . . (has) contributed the largest share toward this accom- 
plishment. To me (its) work has meant an awakening and uplifting hardly 
equalled by any other influences that have worked upon my soul. May your 
anniversary week be a thorough success. 

Professor M. P. E. Grossmann, 
Milwaukee, Wis. 

Allow me to extend cordial congratulations on the auspicious event. 

Professor Charles W. Hargitt, 
Syracuse University. 

I extend for the University of Maine hearty congratulations, and wish con- 
tinued prosperity for the future. 

President A. W. Harris, 
University of Maine. 



38 Extracts from 

I send you my hearty congratulations on your decennial celebration. 

President Waltek L. Heevet, 

Teachers' College, New Yorh City. 

I congratulate you and the Trustees and Faculty upon these successful years 
of your University work, and upon this most appropriate mode of celebrating 
the anniversary. It is a mode worthy of universal following, and will, without 
doubt, be more and more adopted by our institutions of higher learning. 

Propessok G. H. Howison, 

University of California. 

Allow me to offer my congratulations to you especially, and to your associ- 
ates, for the marked success which has attended the career of Clark University. 
We have felt that it not only increases the resources of high education for 
youth, but it stands for progress and enlightenment in the commonwealth and 
the country at large. There is a justifiable pride on the part of those who love 
earnestness and progress in educational matters, as they review the past of this 
institution, into whose good name and wide scope of influence you have thrown 
so much of your personal enthusiasm as well as your scholarly ability. 

Eev. Edwakd a. Hokton, 
Boston, Mass. 

I have many pleasant memories of a year's profitable work at Clark, and 
rejoice in the continued success of Clark University. 

Professor L. S. Huleurt, 

Johns Hopkins University. 

The programme presented is most attractive and inspiring. I congratulate 
you upon the successful work of the past ten years. 

Dr. Henry M. Hurd, Baltimore, Md., 
Superintendent Johns Hopkins Hospital. 

I can't help expressing to you my feeling of satisfaction, and repeating the 
satisfaction I heard such men as Cattell, Eoyce, Van G-ieson, Milnsterberg, and 
Putnam express, with the excellent good taste and refinement of your little 
celebration. All the refinements of the world seem now to take refuge in the 
smaller things ; the bigger ones are getting too big for any virtue to remain with 
them. You have done something original and succeeded perfectly, from the 
point of view of the passive " assistant." 

Professor William James, 
Harvard University. 

I beg you to accept my heartiest congratulations. Each year, I sincerely 
believe, finds me more grateful and appreciative of the privileges I enjoyed at 



Congratulatory Letters. 39 

Clark, and especially do I realize more and more what you yourself did for me. 
I trust you may be spared health and vigor many years to come in your labor, 
for you are doing a great work. 

George E. Johnson, Andover, Mass., 
Superintendent of Schools. 

I have been very deeply interested in the work of Clark University, and in 
the way it has held to its high purposes regardless of pressure of all sorts in 
other directions. . . . Stanford congratulates Clark on ten years' noble work 
for high thought and accurate investigation. 

Pkesldent David S. Jordan, 

Leland Stanford Jr. University. 

Per myself and all the staff of the University of California, I send you 
hearty congratulations and good wishes. You have not attempted to do as 
many things as some other universities, but what you have attempted you have 
done exceedingly well. If excellent work is the standard of true success, you 
have been successful among the foremost. 

May your achievements and your reputation gain still greater lustre, and 
your educational work confer still larger benefits on succeeding generations. 

President Martin Kellogg, 

University of California. 

May I say that I think you have taken a most admirable course in the char- 
acter of this celebration, and that I wish you every success, not only on this 
occasion, but in all the future years of the University. 

Professor J. S. Kingslbt, 

Tufts College. 

I regret more than I can express my inability to be present at the decennial 
celebration of your noble institution, and to hear the splendid series of lectures 

which you have provided. 

Professor Joseph LeConte, 

University of California. 

It is a pleasure to me to join in the celebration of the first decade of Clark 
University. The method of celebrating the event is, I think, exceedingly fit- 
ting. I enjoyed several of the most interesting years of my life in the lectuie- 
rooms and laboratories of Clark, and always recall them with great satisfaction. 

Professor J. S. Lemon, Washington, D.C., 
Columbian University. 

Clark University stands unique among the universities of this country in the 
work which it is attempting to do. No other institution has done more in the 



40 Extracts from 

line of original investigation, nor given during the same period greater inspirar 

tion to the educators of the country. 

Professor G. W. A. Lucket, 

University of Nebraska. 

Permit me to congratulate heartily the President, Trustees, and the Faculty 
of Clark University upon the completion of the tenth academic year of the 

University. 

Pkesident George E. MacLean, 
University of Nebraska. 

We appreciate the great work done by Clark University, and send every best 

■wish for the future. 

President James G. K. McCldre, 
Lake Forest University. 

I have the highest feelings of regard for Clark University, for I feel that I 
owe much to it. Its conception is the broadest and best of all our institutions, 
and I hope the time vfill come when it can broaden out, and, all obstacles 
being removed, go on to its full completeness. 

Professor William S. Miller, 
University of Wisconsin. 

When one thinks of the amount of light that has spread from Clark Univer- 
sity and of the place that it fills in American education to-day, it is hard to 
realize that no such institution was in existence ten years ago. Please accept 
my most sincere congratulations to this auspicious event, with the hope that a 
long series of years of vigorous activity may be granted to jon, so that you may 
lead the University to ever new achievements, and continue to benefit the cause 
of education in the future, as you have so splendidly done in the past. Vivat, 
floreat, crescat. 

Professor F. Monteser, 

New York University. 

It is with very great regret that I find it impossible to attend the rich cele- 
bration you have prepared for the friends of Clark University and of all the 
forward movements iu science for which you have made Clark University stand, 
and wish the University long-continued and increasing prosperity. 

Professor E. H. Moore, 
University of Chicago. 

My participation in the treasures you offered was thus limited to one day — 
but this one day, with the three lectures I listened to, and the very interesting 
men I met, was so agreeable and valuable that I feel the desire to thank you 
warmly for the distinguished and exquisite pleasure. I take special pleasure 
in combining with my personal thanks my congratulations to the high success 



Congratulatory Letters, 41 

of tte celebration and my very best wishes for tlie next ten years in the life of 

Clark University. 

Peofessor Hugo Munsteebeeg, 
Sarvard University. 

Permit me to express here my sincere admiration and respect for the aims, 
ideals, and plans of Clark University ; these are of such an ideal character that 
they are bound to interest profoundly every man who loves science for its own 

sake. 

Pkofessor J. TJ. Nep, . 

University of Chicago. 

Permit me to offer my hearty congratulations on the work done and the 
progress made in the ten years of Clark's existence, to express the hope that the 
future may be marked by even greater achievements. 

Pkesident CTEns Northkop, 
University of Minnesota. 

Clark University does well to celebrate in such a becoming manner the noble 
service which she has rendered to higher education in this country. May the 
next ten years be no less fruitful and helpful to those who have become 
accustomed to look to Clark University for inspiration and guidance. 

Professor F. W. Osboen, 

Adelphi College, Brooklyn, iV. T. 

I write to congratulate you most cordially upon your celebration of the com- 
pletion of the tenth academic year of Clark University. 

Professor Henet F. Osborn, 

Columbia University. 

Allow me to congratulate you upon these lectures, and also upon the remark- 
able results which you have been able to accomplish in ten years in connection 

with Clark University. 

Peofessoe G. T. W. Patrick, 
University of Iowa. 

The Provost, Trustees, and Faculty of the University of Pennsylvania 
present their cordial congratulations to the President, Trustees, and Faculty of 
Clark University on the happy completion of the tenth academic year of the 
University. 

The President, Trustees, and Faculty of Clark University certainly deserve 
the thanks of all those interested in the cause of education. 

Professor George H. Price. 
Vanderbilt University. 



42 Extracts from 

Pray accept congratulations on the completion of a decade of grand work, 
and on the prospects of even better work for the future. 

John T. Pkinoe, West Newton, Mass., 
Agent State Board of Education. 

I send my heartiest congratulations on the great achievements of Clark 
University during its first decade, and express my sincerest desire that its use- 
fulness may continue and expand for many centuries to come. 

Pkopessor Ernst Richard, 
Ifeio York City. 

President H. W. Eogees (Northwestern University) desires to extend the 
congratulations of Northwestern University, as well as his own, upon the great 
success of Clark University and the distinction it has attained in the academic 
world. 

James E. Eussell (Dean, Teachers' College, New York) wishes to convey 
to the President of the University his best wishes for the continued success 
and prosperity of the institution. 

President L. Clark Seelte (Smith College) offers his hearty congratula- 
tions on the important educational work it has already accomplished. 

With sincere thanks and hearty congratulations on the auspicious occasion, 

Professor James Seth, 

Columbia University. 

Meanwhile I wish to join in the many congratulations I am sure you will 
receive upon the quiet and dignified, but none the less eminent, manner in which 
Clark University has carried on the work of the past decade, and upon the 
manner in which it has reflected honor upon American scholarship in science 
and philosophy. 

Albert Shaw, New York, N. Y., 
Editor Beview of Reviews. 

We shall always be grateful for the work that has already been accomplished 
by the University, and especially for the ideals which it has brought to the 
colleges and universities of the West. With high personal regard and warmest 
congratulations from our faculty. 

President William F. Slocum, 
Colorado College. 

With best wishes for the success of the celebration and for the continued 
prosperity of your institution. 

President P. H. Snow, 

University of Kansas. 



Congratulatory Letters. 43 

Allow me to congratulate the University upon its happy completion of ten 
years' life and work, and to wish it a long and prosperous future. 

Professor Frederick Stark, 
University of Chicago. 

I wish to send my cordial congratulations and my wish that the next ten 
years may witness the coming to the University of such ample endowments 
as will enable it to accomplish its high ideals. 

President James M. Tatloe, 
Vassar College. 

Please accept my best wishes for continued prosperity. 

President W. 0. Thompson, 

Ohio State University. 

I do not like to let the present occasion pass without intimating to you my 
appreciation and admiration of the methods and aims of university work for 
which Clark University has stood in the past, and will, I hope, stand in a 
long and prosperous future. My recent visit to Worcester merely confirmed a 
belief which I have long held, — that the type of man that Clark University 
calls to its professorial chairs, and the type of man that it sends into active life 
at the close of its three or four years of graduate study, are types that represent 
the highest ideal of scholarship, and are the very salt of American society. I 
hope, most sincerely, that the coming celebration will prove to be the door 
through which you and the University pass to greatly extended activity upon 

your own high level. 

Pkofessor E. B. Titchenek, 
Cornell University. 

I wish to express my sincere appreciation of the service to education and 
investigation which Clark University is thus undertaking, a service which is 
eminently in harmony with the work of Clark University from the beginning. 

Professor James H. Tofts, 
University of Chicago. 

I wish to extend my hearty congratulations on the successful work of the 
University during the last ten years, and my best and most hearty good wishes. 

Professor John M. Tyler, 
Amherst College. 

Professor Henet B. Ward (University of Nebraska) extends to the 
President, Trustees, and Faculty his congratulations upon the occasion, and 
best wishes for the continued success of the institution. 



44 Extracts from Congratulatory Letters. 

I express my sincere congratulations. 



Professor Sho Watase. 

University of Chicago. 

With best wishes for the success of the University, 

Pkopessor J. B. Weems, 
Iowa State College. 

Please accept congratulations upon the honorable record of these ten com- 
pleted years. The distinguished service of yourself and the University have 

made the whole world your debtor. 

President B. L. Whitman, Washington, D. C, 
Columhian University. 

The Clark University ideal as I understood it, when connected with its 
early work, is the ideal which I place above any others thus far proposed, and 
I hope that it may find strong friends to help it forward. 

Professor Charles 0. Whitman, 
University of Chicago. 

Professor A. W. Wright (Yale University) sends congratulations and 
best wishes for the prosperity of the University. 



DECENNIAL ADDRESS. 

By G. Stanley Hall, President of the University. 

It has been said that decades are the best periods for studying historic 
tendencies because they are long enough to contain a rich array of facts 
and events, and short enough to be grasped by a single mind in the stage 
of its prime. The ten years since Clark University was opened, the close 
of which, by the cooperation of a few beneficent public-spirited citizens of 
Worcester, we have sought to mark in a very quiet but digniiied way that 
should befit at once its size and its quality, constitute distinctly the most 
important decade in the educational history of this country. The mere 
index of a few of the well-known and accomplished facts of these years 
has an eloquence beyond all words. They have witnessed the establish- 
ment of the Catholic University at Washington, with its strong faculty 
and its handful of picked graduates from the seventy Catholic colleges 
of the country, the only university in the land besides Clark devoted 
solely to graduate work, an institution related to us, not only by a 
strong tie of sympathy in the struggle and sacrifice for ideals and high 
standards, but by my own long and personal friendship with the first 
rector, and by the fact that its present head was our Worcester neighbor 
and kindly friend. The Leland Stanford University, now one of the 
richest in the world, was planned and endowed by a long-time friend of 
our Founder, and the wife of that founder lately told me that she still 
counts ours among her wisest and most trusted advisers. The University 
of Chicago, with possibilities of increase brighter and larger than any 
other, from the very first the most rapid academic growth in history, has 
leaped into existence with a Minerva-like completeness, owing in no small 
part its first impulse to higher creative work in science to the sagacity of 
the chief trustee of its Ogden Fund, our fellow-townsman, Andrew H. 
Green, and which is still more closely affiliated to us by the fact that so 
many of the leading members of its faculty honored us by doing three 
years of their best work here, and for which we still cherish a little of 

45 



46 Decennial Address. 

the feeling of a poor but proud and noble mother for her great son. The 
new Methodist University at Washington has begun the unfoldment of 
large and well-matured plans, for the fulfilment of which the vitality of 
the strong religious body behind it is perhaps the best of guarantees. 
The millions already provided and about to be expended at the State 
University of California which will involve transformation and enlarge- 
ment perhaps greater than all that has hitherto been done there, very 
comprehensive and valuable as that is ; the magnificent new architectural 
installation at Columbia and the federation of so many other affiliated 
institutions about it, with all the possibilities of our greatest metropolis 
open before it ; the steady development, whether for good or for ill, of 
the plan of a great national university, to which at least all state, if not 
private, colleges and imiversities may be tributary as feeders, and which 
shall command all the vast resources of science in Washington, unify 
them, and add the new vitalizing function of research and perhaps teach- 
ing, a scheme that has enlisted most of the educational leaders of the 
land and is sure of eventual fulfilment, — such are some of the events 
which have seemed to many to thi-eaten the academic preeminence of 
New England, and even of the East, in the future ; that have stirred to 
their very foundations the older and more conservative institutions, and 
caused transformations not all apparent from the outside, but which 
involve hardly less than an ultimate revolution of academic sentiments, 
methods, and ideals. Fellowships, not for the indigent who need support 
while preparing for the professions, but to give leisure, opportunity, and 
incentive for full development to talent, the choicest of all national prod- 
ucts ; research, with books, apparatus, above all, leaders competent to 
guide and inspire ; new post-graduate departments for non-professional 
specialization, with their own laboratories and libraries ; seminaries where 
experts discuss the latest literature, best methods, instruments, and 
results of investigation ; new journals devoted to the speedy publication 
of such studies ; new chairs and topics ; a growing and ever widening 
distinction between receptive learning and active creation, — these and the 
gradual completion of a system that is truly national, and has not its 
apex in Europe, where hundreds of our graduates still go yearly to get 
what it should be a matter of simple patriotism to supply at home, must 
suffice to mark the direction and progress of these years in which institu- 
tions and work alike are becoming more and more plastic to the changing 
and ever more imperative needs of learning and science which have them- 



Decennial Address. 47 

selves celebrated triumphs during the decade which could not even be 
enumerated within the hour. It is no wonder that many old academic 
problems have become obsolete and new ones have arisen, and that j^i'es- 
ent demands in men, methods, and instruments have changed from those 
of ten years ago. 

Again, within this time a wave of doubt and opposition to the public 
support of intermediate education passed over the country, but the reac- 
tion against that tendency has made the last few years preeminently the 
age of high schools. More and statelier buildings than ever before, 
longer courses and more of them, many modifications suggested by 
committees and others, great increase in the number of students, rich 
and well-planned departures like the Tome Institute, Mrs. Emmons 
Blaine's new normal foundation, and several others contemplated or 
assured but not yet established, the new associations of high schools 
and colleges covering now all sections of the country, the ever increas- 
ing collegiate character of the work done in such institutions, and the 
consequent development of a distinct, and in some places urgent, small 
coUege problem, — all this shows that even secondary education, the last 
stage to be reached by reforms, has here been stirred and quickened as 
never before. 

If we extend our view to lower grades, we find aU plastic and chang- 
ing. This stronghold of conservatism is invaded by the spirit of reform, 
often revolution, and sometimes even of rather wild experimentation. 
New journals, pedagogical chairs, new methods, the new school hygiene, 
broader views that relate teaching to all the great problems of science, 
statescraft, and religion, have arisen, which have brought the university 
and kindergarten and all between them into an organic unity, yet fitting 
all features of the system to the vast variety of individual differences of 
character, temperament, and ability. In this field, I think, the closing 
decade has witnessed a change greater than the preceding quarter of a 
century. New and better minds are enlisted, educational topics are of 
increasingly central interest in the press and more dominant in the 
church and pulpit, education is becoming more professional and scientific, 
recognizing the necessity of expert leadership and mastery, and is at last 
assuming its rightful and larger power, and its normal basal all-condition- 
ing place as at bottom a biological science, revealing to us how state, 
church, home, literature, science, art, and all else have their ultimate 
justification only in so far as they are effective in bringing human beings 



48 Decennial Address. 

to the ever fuller maturity of mind and body on which civilization de- 
pends, and which it is the work of education to accomplish in the world. 
This is increasingly necessary as our country grows in population and in 
territorial expansion, and educational progress is coming to be recognized 
by history as the chief standard by which to test all other advancement. 
Europe has progressed during this decade, although with less rapidity, 
along nearly all these lines, and the next decennial promises not less, but 
more advance. In such a time it is, indeed, glorious to be alive, and to 
be young is heaven, for hope is even brighter than memory. 

No time in the history of the country could have been more favorable 
than the beginning of this period for a great and new university founda- 
tion. The epoch-making work of the Johns Hopkins University, which 
for the preceding decade had made Baltimore the brightest spot on the 
educational map of the country, and was the pioneer in the upward move- 
ment, had leavened the colleges and roused them from the life of mo- 
notony and routine which then prevailed, and kindled a strong and 
widespread desire for better things. The significance of the work of 
that institution can hardly be overestimated. But financial clouds had 
already begun to threaten this great Southern luminary, and there were 
indications that, if the great work it had begun was to be carried on, 
parts of it, at least, must be transplanted to new fields. 

It was at this crisis that our munificent Founder entered the field with 
the largest single gift ever made to education in New England, and one 
of the largest in the world, and with the offer of more to come, if suffi- 
cient cooperation was forthcoming. He selected Worcester as the site 
of his great enterprise with a piety to the region of his nativity worthy of 
the greatest respect and emulation, and in addition to the fulfilment of 
his pledges gave it the benefit of his own previous wide studies of educa- 
tion in Europe, and contributed wisely matured plans and constant per- 
sonal oversight and labor for years. It is as strenuously engaged in this 
highest of all human endeavors that the world knows him, and that we 
shall remember him, and I am sure that we all unite to-day first of all 
in sending him in the retirement his health demands (although it cannot 
assuage his interest to see the work of his hands prosper) our most cordial 
greetings and our most hearty congratulations. 

With a dozen colleges within a radius of one hundred miles doing 
graduate work, the plainest logic of events suggested at once a policy of 
transplanting to this new field part of the spirit of the Johns Hopkins 



Decennial Address. 49 

University, and taking here the obvious and almost inevitable next step by 
eliminating college work, although the chief source of income by fees was 
thereby also sacrificed, and thus avoiding the hot and sometimes bitter 
competition for students, waiving the test of numbers, and being the first 
upon the higher plane of purely graduate work, selecting rigorously the 
best students, seeking to train leaders only, educating professors, and ad- 
vancing science by new discoveries. It was indeed a new field wide open 
and inviting, the cultivation of which was needed to complete our 
national life ; the preliminary stages of its occupancy all finished, yes, 
necessary almost as a work of rescue for the few elite graduates who 
wished to go beyond college but not into any of the three professions, 
and who had had hitherto a pathetically hard time. The call to the 
President gave assurance of the highest aims and of perfect academic 
freedom, a pledge that has been absolutely kept. He was sent to Europe 
a year on full pay to learn the best its institutions could teach, and the 
Faculty that first fore-gathered here has never been excelled in strength, 
if indeed it has ever been equalled anjrwhere for its size. Story, an 
instructor at Harvard, colleague and friend of Sylvester, formerly acting 
editor of the chief mathematical journal of the country and co-head of his 
department at Baltimore, founder of another journal here, who has 
enriched his department by contributions, the list of which printed else- 
where in this volume tells its own story ; Michelson, who while here 
accepted an invitation of the French Government to demonstrate in Paris 
his epoch-making discoveries in the field of light, which he did while on 
our pay-roll — lately especially honored by learned societies at home and 
abroad, now head of one of the best-equi^jped and largest laboratories in 
the world, and still continuing his brilliant contributions to the sum of 
human knowledge ; Whitman, now head of another great university 
laboratory, trainer of many young professors, founder and editor of 
the best and most expensive biological journal, head of Woods HoU 
marine laboratory and summer school, one of the best of its kind in the 
world, himself a contributor to his science ; Michael, than whom America 
had not produced a more promising or talented chemist, the list of 
whose published works would be far too long to read here ; Nef, perhaps 
our most brilliant young chemist, and now head of one of the largest 
and best-equipped laboratories in the world, and with a power of sus- 
tained original work rarely excelled ; Mall, now full professor at the 
Johns Hopkins University, and head of the great new anatomical labora- 



50 Decennial Address. 

tory and museum there, whose published contributions are admirable 
illustrations of both the great caution and boldness needed by a student 
in his field ; Boas, the leading American in physical anthi-opology, no-w 
a professor at Columbia ; Loeb, almost the first expert that this country 
could boast in the new physical chemistry in the sense of Ostwald, now 
head of his department in the University of the city of New York; 
Bolza, an almost ideal teacher, suggesting the great Kirchoff in the per- 
fection of his demonstrations ; the brilliant and lamented Baur, leader 
of the expedition to the Galapagos Islands made possible by the gift of 
Worcester's patron saint of so many good enterprises, Mr. Salisbury; 
Donaldson, now dean of the graduate school of the University of 
Chicago, author of the best handbook in English on the brain, with 
a caution, poise, and diligence befitting the successful investigator in that 
dangerous but fascinating field ; Mulliken, suddenly placed in a position 
of great difficulty, discharged its duties with rare ability and discretion 
for one so young ; Lombard, now professor in Michigan, genial, assiduous, 
a gifted teacher and enthusiastic student ; White, scholarly, able, a born 
teacher and student ; McMurrich, an untiring investigator and a lucid 
inquirer after knowledge ; those now here, who have since become so 
well-known, Burnham, Chamberlain, Hodge, Perott, Sanford, Taber, and 
Webster ; these, not to mention many others, then only fellows, but who 
have achieved so much in their work and positions since, — these are the 
men and others whose presence on this spot, whose high intercourse and 
whose stimulating personal contact with each other, whose ardor and devo- 
tion in the pursuit of knowledge, whose healthful emulation in achieve- 
ment, made this almost classic ground and the cynosure of the eyes of 
all those in this country who love science for its own sake. With the 
wealth, wisdom, and interest of our Founder, with the high character 
and culture of our Board of Trustees, with the intelligence of such a 
community of old New England, with an atmosphere of intellectual free- 
dom, with unique and precious exemption from the drudgery of excessive 
teaching and examinations, with the youth of the Faculty, none of whom 
had reached the zenith of their maturity, with substantial and ample 
buildings, abundant and forthcoming funds for equipment, few rules and 
almost no discipline or routine of faculty meetings, the motto on our seal, 
fiat lux, our university color white, — is it any wonder if some of our 
young men saw visions and dreamed dreams, or perhaps in some cases fell 
in love with the highest ideals, or that the very memory of the first stage 



Decennial Address. 51 

of our history is to-day, as it has been in darker hours, a most precious 
memory and a basis of an all-sustaining hope ? 

To these days of our prime to which our former students and profess- 
ors recur with joy, and in whose breasts the processes of idealization of 
them have already begun, days which were pervaded by sentiments of joy 
and hope very like those which animated the best years of the Johns 
Hopkins University, we have often reverted since in soberer hours with 
longing thoughts of what might have been had the University continued 
in all its pristiiie strength. Not one weak, dull, or bad man in our Faculty, 
all given not only leisure, but every possible incentive to do the very best 
work of which they were capable, with a Founder and a board of control 
who realized that a new endowment should do new things, and that the 
best use of money is to help the best men, we entered a field very largely 
new and with as bright prospects as we could wish. 

But life has its contrasts and competitions. The reductions of our 
force, which occurred at the end of the third year, sad to us almost beyond 
precedent, although helpful elsewhere, may be ascribed to fate, disease, 
or to the very envy of the gods. Some incidents should remain unwritten, 
but it should be known that our Trustees foresaw from the beginning of 
the year one of the gravest of crises, and met it with an unanimity, a 
wisdom, and a firmness which even in the light of all that has transpired 
since, I think, could not be improved on. The pain of it all has faded, 
the glad hand has been extended and accepted by nearly if not quite all 
who left us ; the lessons of adversity have been learned and laid well to 
heart, and we hope and believe that these and all their attendant incidents 
may be considered closed. 

Although nearly half our Faculty and students left us in the hegira, 
and our income had dropped in almost the same proportion, and only the 
departments of psychology and mathematics remained nearly intact, we 
fortunately had left in every department young men as promising as any 
in the land. They needed simply to grow, and never has there been such 
an environment for a faculty to develop as in this "paradise of young 
professors," as a leading college president has called this University. To 
Darwin the greatest joy of life was to see growth ; and to see the unfold- 
ment of these youthful, intellectual elite, and to feel the sense of growth 
with them as all near them must, is a satisfaction almost akin to the 
rapture of discovery itself. Now the years have done their work, and 
our Faculty, although smaller, was never stronger, never more prolific, 



52 Decennial Address. 

stimulating, and attractive to students, in proportion to its size, than it is 
to-day. There has never been such loyalty to the institution and its 
ideals, such readiness to endure the petty and the great economies now 
necessary, such prompt and frequent refusals of larger salaries elsevp'here, 
and so strong a sentiment that, so long as a man has growth in him, our 
incentive, opportunity, and plan of work are of more value than a large 
increase of salary. 

These changes involved, however, but little reduction of the number 
of instructors or of students, but materially decreased for a time the effi- 
ciency of the University. Since the end of the third year the President, 
who was not required to teach, has done full professorial duty in addition 
to that of administration, has established a seminary at his house three 
hours each week through the entire academic year, and founded and con- 
ducted at his own expense a new educational journal. The income-bear- 
ing summer school has been organized and conducted during the past 
seven years with the active and efficient cooperation of a large local 
advisory board under the direction of Colonel E. B. Stoddard and Charles 
M. Thayer, Esq., by which its social character, that has contributed 
much to its success, has been established on a high plane. The summer 
school represents only the departments of biology, psychology, and peda- 
gogy, is open to every one of either sex on the payment of a small fee, is 
popular rather than technical in its scientific character, has been numer- 
ously attended, and in all ways is directly in contrast with the work of 
the year. Hardly a ripple has marred the harmony within the Univer- 
sity during these last seven years, and every man, student and instructor 
alike, has been hard at work and enthusiastic for our own unique and 
individual method and plan. 

This institution must be judged from within and by educational and 
scientific experts, and the commendations which we have lately received 
from leading specialists, some of which are printed elsewhere in this 
volume, have been so numerous, spontaneous, and hearty in response to 
our invitation to be present, as almost to rival in cordiality and loyalty 
to the now so definitely developed Clark idea and Clark spirit that of 
our three alumni associations of the Pacific Coast, Illinois, and Indiana 
organized during the present year. 

Scientific work must be weighed and not measured, so that numbers 
tell but little. Clark University has been instrumental in training well- 
nigh three hundred professors or special academic instructors, has numbered 



Decennial Address. 53 

over twelve hundred different persons enrolled in its summer school, not 
counting the hundreds who have attended more than one session. These, 
especially the former, are in a sense our epistles known and read of all 
men. The other output of a university like ours is its scientific work, 
and here we have five hundred publications based upon work done here, 
of which twenty-five are books. The University now publishes three 
journals, with hope of a fourth as a more permanent way of marking the 
beginning of its second decade. 

Small as we are, if our departments and students are measured by the 
significant criterion of the number of the doctorates annually conferred 
here, we rank among the best and largest institutions of the land. Al- 
though our fellowship funds have declined, and that, too, in the midst 
of a competition, which never existed or was hitherto dreamed of, our 
numbers of late years have slightly but steadily increased, although at 
the same time we could go on forever and do invaluable work of research 
and publication like the French Ecole des Hautes Etudes, or a few other 
Old World institutions, even if we had no students ; and, indeed, America 
may need in the future, if, indeed, she does not already, at least, one such 
academic endowment for research only. One thing, at least, is true so 
far, hardship has no whit lowered our aims or diluted our quality, but if 
anything has had the reverse influence ; and I fervently trust (and think 
I can speak on this point with confidence for the entire Faculty) that this 
may be the case throughout all the infinite future that endowments like 
this in a country like ours have a right to expect. Although influences 
are too subtly psychological to be traced, I am writing our history, and 
find it a most inspiring theme, and I believe it adds already a very bright 
and hopeful page to the records of higher education in the country, and 
one which history will brighten to epochal significance. It has, on 
the whole, in it one clear note, not of discouragement, but of hope and 
confidence. 

Have we duly considered, even the best of us, what a real university 
is and means, how widely it differs from a college, and what a wealth 
of vast, new, and in themselves most educative problems it opens? A 
college is for general, the university for special, culture. The former 
develops a wide basis of training and information, while the latter brings 
to a definite apex. One makes broad men, the other sharpens them to 
a point. The college digests and impresses second-hand knowledge as 
highly vitalized as good pedagogy can make it, while the university, 



54 Decennial Address. 

as one of its choicest functions, creates new knowledge by research and 
discovery. The well-furnished bachelor of arts, on turning from the 
receptivity of knowing to creative research, is at first helpless as a 
new-born babe, and needs abundant and personal direction and encour- 
agement before he can walk alone ; but when the new powers are once 
acquired they are veritable regeneration. He scorns the mere luxury 
of knowing, and wishes to achieve, to become an authority and not an 
echo. His ambition is to know how it looks near and beyond the 
frontier of knowledge, and to wrest if possible a new inch of territory 
from the nescient realm of chaos and old night, and this becomes a new 
and consuming passion which makes him feel a certain kinship with the 
great creative minds of all ages, and having contributed ever so little, 
he realizes for the first time what true intellectual freedom is, and attains 
intellectual manhood and maturity. This thrill of discovery, once felt, 
is the royal accolade of science, which says to the novice, stand erect, 
look about you, that henceforth you may light your own way with 
independent knowledge. 

This higher educational realm is full of new " phenomena of altitude." 
Faculties, instead of discussing and elaborating plans for commencement 
ceremonies, hearing recitations, preparing and then reading the results 
of examination papers, and carefully marking each individual exercise, 
grinding in the old mills of parietal regulations, discipline, and the rules 
of conduct needful to civilize the adolescent homo sapiens ferus, revising 
requirements for admission, tacking and shaping the policy to gather 
in more students and keep ahead of others in the struggle to get the best 
connections with high and fitting schools, are occupied with far different 
problems wherever the university spirit has a true and real embodiment. 
Here first of all men must be discriminated, and great issues hang upon 
the success in differentiating superior from indifferent young men. To 
detect the early manifestations of talent and genius in the different fields 
of intellectual endeavor, which some presidents and professors can, and 
others so eminently lack the power to do, is the crucial doorkeeping 
problem, where great privileges are to be awarded to great promise. 
This is almost a life and career saving function for not only the young 
professors and students, but for the university. Men are not equal, and 
there must be a touchstone of mental aristocracy to discriminate $500 
from 110,000 men. 

Second, having selected these, the university should bestow freely its 



Decennial Address. 55 

needed aid and equipment, and the professor his choicest time and 
knowledge, to perfect the precious environment by which the later stages 
of growth, so liable to be lost, but on the full development of which 
civilization itself hangs, and perfected. How to select the best, ripest, 
and most fruitful topics for investigation requires an almost prophetic 
ken in which differences in individual professors are immense. To study- 
individuals enough to adapt each theme to each personality is another 
problem as new as it is delicate and difficult. The right solution of both 
these is the large half of the work. The professor should give his best 
suggestion, with no reservation for himself, and the able student should 
not be an apprentice to serve his master, but should be distinctly 
educated toward leadership himself from the first. 

Having thus sown fit seed in fit soil, it must be watched and watered 
with constant suggestion. The best and newest literature ; the most 
effective and original apparatus that can be devised and if possible 
made on the spot ; how to insure in the best form and place the speedy 
publication of work and to bring it under the eye of all experts ; how 
to avoid conflict and duplication ; how general or how special thesis sub- 
jects and work should be to best combine the two sometimes more or 
less divergent ends of discovery and education ; the requirements for 
perhaps the choicest of all degrees, the doctorate of philosophy ; the best 
modes of individual examination for it ; the number and relation of 
subjects required ; the migration of students so as to insure not only 
the best environment for each, but to give to professors not only in the 
same department, but in different institutions, the same stimulus that 
was felt when the elective system aroused the dry-as-dust professors to 
unwonted effort lest their class-rooms be left vacant ; the kindred ques- 
tion of the relative value of graduate work at home and abroad for 
each student and for each department ; the fit federation of graduate 
clubs and their thirty-five hundred members in the twenty-three Ameri- 
can institutions now recognized in the yearbook ; the great problem of 
printing and special journals together with interchange of monographs ; 
the vast new library problems of purveying for highly specialized, but 
very voracious, appetites which make the true university librarian a man 
of far different order from others, and gives him a wealth of new prob- 
lems of exchange, foraging, etc. ; to maintain the true relations between 
lecture work and individual guidance while duly emancipating the pro- 
fessors from the drudgery of elementary teaching and mass treatment 



56 Decennial Address. 

of great bodies of students ; the many and wide-reaching differences 
between pure and applied science, and the practical methods by which 
this distinction is maintained ; the danger of great aggregations of 
students and the advantages of few ; the wide differences between the 
new kind of professor needed in the university and those in the college, 
where no provision is made for the advancement of learning, and the 
tests are mainly pedagogic ; the even greater contrasts between scholar- 
ship funds for the aid of poverty to professional careers, which are a 
doubtful advantage even in colleges where they belong, and the true 
university fellowship as above described ; the growing dominance and 
need of expertness in all fields for which graduate departments must 
prepare as well as for professorship alone, — these and many great ques- 
tions like them, destined more and more to eclipse all others which are 
just looming up, and for the irrigation and ventilation of which we hope 
to establish here soon a new educational journal — such questions con- 
stitute this opening field of what may be called the higher educational 
statesmanship. 

The hastiest glance at the situation on an anniversary like this would 
be incomplete unless we turned toward the future. Our own needs here 
are many and our wants urgent, but our faith is firm that in a community 
like this the time will soon come when no wills will be drawn by wealthy 
people without carefully considering the conclusion of the largest parlia- 
mentary report ever made, which fills near a score of volumes, was many 
years in the making, and describes all the public bequests ever made in 
England. The substance of the conclusion of that most competent tribu- 
nal that has ever spoken upon this subject is that the best of all uses of 
public benefactions is, not for charity to the poor or even the sick and de- 
fective, noble and Christlike as those charities are, not for lower education 
or religion, beneficient as these are, but rather for affording the very best 
opportunities for the highest possible training of the very best minds in 
universities, because in training these the ivhole work of church, state, school, 
and charity is not only made more efficient, but raised to a higher level, and 
in this service all other causes are at the same time best advanced. I beg 
respectfully, but with all my heart and mind, to urge this conclusion by 
the highest human authority upon all those contemplating the bestow- 
ment of funds where they will accomplish most for the good of man. 

Our very best department is the library, which is so well endowed that 
we do not at present need to expend the income of the fund. In this 



Decennial Address. 57 

respect the sagacity and benevolence of our Founder has been more than 
sufficient for our needs up to the present time, and our most efficient and 
courteous librarian has found many means and devices, new to the most 
advanced library science, of bringing out its utmost efficiency for our 
work, and of making it in all the pregnant sense of that word attractive 
to all who once come within the sphere of its influence. His work amply 
merits all the growing recognition that it and his rare personnel are 
so steadily gaining. His special report contains new suggestions and 
experiences. 

The large and new demands upon the Public Library caused by the 
presence of an university for research which involved a material addition 
to its work, which is likely to increase in proportion to our growth, should 
be distinctly recognized. The special privileges needed by investigators 
have often been a strain upon the capacity of both its officers, its methods 
of administration and service, and the resources of its alcoves. The 
Public Library has on the whole well met the test, and I desire here to 
express, not only for myself personally, but for the other members of the 
University our gratitude to the city, the Trustees, and particularly to the 
accomplished head of the library itself, whose cooperation, with his able 
corps of assistants, has been a factor in an important part of our work. 

Our two strongest departments are mathematics and psychology. 
These two, as has been often said, are the root and heart of all other 
branches. Mathematics is the grammar of all the sciences that deal with 
inanimate nature, and the study of the human mind and soul opens the 
field where all animate nature celebrates her highest triumph and which 
underlies all the humanities. While we could expend with profit much 
more than at present, perhaps the entire resources of the University, upon 
these departments, or perhaps, even upon each of them, they are best 
equipped and least in immediate need. We have books, journals, pro- 
fessors, means of speedy publication, and well-developed traditions, and 
can claim, we think with modesty, to be doing creditable work. 

Our greatest and most pressing need, according to the policy first 
formulated of strengthening the departments already established before 
founding new ones, is to enlarge the biology to an independent position, 
with due provision for botany and the related subject of paleontology. 
The foundations of a building for this group of studies is already laid 
on the grounds, and its completion, with an endowment of $150,000 or 
3,000 with what we now have, would give us a strong department able 



58 Decennial Address. 

to compete successfully with the best ; perhaps we may sometime dedi- 
cate siich a building and department to the name of some honored public- 
spirited citizen of Worcester. 

Physics, like biology, now represented by a single able and promising 
man, needs enlargement to the same degree, with an amiex department 
of astronomy and astrophysics, and for the same sum could, in addition 
to what we now have, be put upon a creditable footing. 

The chemical building, admirably planned after careful studies of all 
the best in Europe, and well equipped, especially for organic work, has 
no endowment, and needs for its full development the income of at least 
a quarter of a million of dollars. 

Anthropology, so greatly needed in this land, but so lacking in 
academic installation and tradition here, is already a precious germ with 
one worthy representative, has been cherished from the first with us, 
and it, too, needs enlargement and independence. 

If we pass over into the humanities, there are, of course, the two 
great groups of philology and literatui-e, ancient and modern, and a 
historical group culminating in political economy, sociology, and a grand 
department of international law, nowhere adequately represented in this 
country, and for the establishment of which somewhere Senator Hoar, 
acting president of the Board of Trustees, the first citizen of Massachu- 
setts, competent to-day to fill any one of four professional chairs in any 
university, in learning, experience, character, and position more nearly 
the American Gladstone than any other, has been so distinguished an 
advocate. 

Education, now coming to be the largest philosophy of life and the 
natural field of applied psychology, needs a more adequate representa- 
tion, and with a quarter of a million of dollars for an ideal university 
school for children, we would almost guarantee in five years to make 
this place an educational Mecca, by short circuit methods now well 
demonstrated but nowhere embodied, which would greatly increase the 
efficacy and reduce the expense and ease the labor of the lower grades 
of education in this country. 

Our summer school has become one of the largest and highest 
grade institutions of its kind in the country, and appeals especially to 
heads of fitting schools, with whom it would be important for us to be 
en rapport if we had a college ; to normal schools, whose faculties are 
a growing field for the employment of our pedagogical graduates ; to 



Decennial Address. 59 

young instructors in colleges, superintendents, parents, etc. If our two 
weeks could become a summer quarter counting toward a degree, and 
if the summer school could be adequately endowed and furnished, with 
the interest which one department of our work has already enlisted 
among the teachers of our country, the best of whom could spend their 
summer here in work, this, too, could be made an institution of which 
any city or university might well be proud. 

We urgently need without delay the means for establishing a univer- 
sity printing office, where we can publish our journals at less expense and 
do our own printing ; and if this should grow to larger dimensions and 
develop a life of its own, that, too, might be welcomed. 

These needs are all on the university plane, where the beginnings 
already made are precious beyond words, wrought out as they have been 
with so much pain and labor, and the highest effort of so many choice 
spirits. May the day never dawn when this in our country most sorely 
needed and prayerfully cherished academic tradition shall fade or be 
broken. The investments of wealth and effort already made are too 
great, and achievements already attained and future promise too bright, 
to permit this ever to be an open question here. 

Satisfied, yes proud, as we are to-day to submit to Worcester, to sister 
institutions, and the country, the records of our work when compared with 
our means, we have lived, and even now live and walk, let us confess it, 
to a great extent in faith and hope, looking confidently to a future larger 
than our past has been, with steadfast and immovable conviction that our 
cause is the very highest of all the causes of humanity, but ready even 
ourselves, if need be, to labor on yet longer in the captivity of straitened 
resources, being fully persuaded that our redeemer liveth and that in due 
time he shall appear. 



THE DEPARTMENT OF MATHEMATICS. 

By William Edward Story. 

PAST AND PRESENT STAFF. 

William Edwaed Stoey, Ph.D., Professor of Mathematics since 1889. 

OsKAR BoLZA, Ph.D., Associate ia Mathematics, 1889-92. 

Henry Tabee, Ph.D., Docent in Mathematics, 1889-92; Assistant Professor 

of Mathematics since 1892. 
Joseph db Peeott, Docent in Mathematics since 1890. 
Heney S. White, Ph.D., Assistant in Mathematics, 1890-92. 

FELLOWS AND SCHOLARS. 

Heney Bennee, Pellow in Mathematics, 1889-90. 

L. P. Ceavens, Scholar in Mathematics, 1889-90. 

KoLLiN A. Harris, Ph.D., Fellow in Mathematics, 1889-90. 

J. F. McCuLLOCH, Fellow in Mathematics, 1889-90. 

William H. Metzler, Fellow in Mathematics, 1889-92. 

J. W. A. Young, Fellow in Mathematics, 1889-92. 

Levi L. Conant, Scholar in Mathematics, 1890-91. 

Alfred T. De Luey, Fellow in Mathematics, 1890-91. , 

James N. Hart, Scholar in Mathematics, 1890-91. 

Thomas F. Holgate, Fellow in Mathematics, 1890-93. 

John I. Hutchinson, Scholar in Mathematics, 1890-91; Fellow in Mathe- 
matics, 1891-92. 

Frank H. Loud, Scholar in Mathematics, 1890-91. 

N. B. Hellee, Scholar in Mathematics, 1891-92. 

Loeeain S. Hulbuet, Fellow in Mathematics, 1891-92. 

John McGowan, Scholar in Mathematics, 1891-92. 

Eenest B. Skinnee, Scholar in Mathematics, 1891-92. 

L. Wayland Dowling, Scholar in Mathematics, 1892-93; Fellow in Mathe- 
matics, 1893-95. 

John E. Hill, Fellow in Mathematics, 1892-95. 

Heebert G. Keppel, Scholar in Mathematics, 1892-93; Fellow in Mathe- 
matics, 1893-95. 

61 



62 Department of 

Thomas P. Nichols, Scholar in Mathematics, 1892-93 ; Fellow in Mathematics, 
1893-95. 

r. E. Stinson, Scholar in Mathematics, 1892-93; Fellow in Mathematics, 
1893-95. 

W. J. Waggenbe, Scholar in Mathematics and Physics, 1892-93. 

Warren G. Bullaed, Scholar in Mathematics, 1893-96. 

Schuyler C. Datisson, Fellow in Mathematics, 1895-96. 

Feedeeiok C. Feeet, Fellow in Mathematics, 1895-98. 

John S. French, Scholar in Mathematics, 1895-96 ; Fellow in Mathematics, 
1896-98. 

E. W. Kettger, Fellow in Mathematics, 1895-98. 

tS. Edwaed Eteeson, Fellow in Mathematics, 1895-96. Died March 25, 1896. 

Hugh A. Snepp, Scholar in Mathematics, 1895-96. 

James W. Boyce, Fellow in Mathematics, 1896-99. 

Heebeet 0. Clough, Scholar in Mathematics, 1896-97. 

A. Harry Wheeler, Scholar in Mathematics, 1896-99. 

Lindsay Duncan, Scholar in Mathematics, 1897-99. 

Feedeeick H. Hodge, Scholar in Mathematics, 1897-98 ; Fellow in Mathe- 
matics, 1898-99. 

Halcott C. Moeeno, Scholar in Mathematics, 1897-98; Fellow in Mathe- 
matics, 1898-. 

Stephen E. Slocum, Scholar in Mathematics, 1897-98 ; Fellow in Mathematics, 
1898-. 

John N. Van dee Veies, Scholar in Mathematics, 1897-98 ; Fellow in Mathe- 
matics, 1898-. 

Frank B. Williams, Scholar in Mathematics, 1897-98; Fellow in Mathe- 
matics, 1898-. 

Elwin N. Lovewell, Scholar in Mathematics, 1898-99. 

Louis Siff, Scholar in Mathematics, 1898-99. 

Oelando S. Stetson, Scholar in Mathematics, 1898-99. 

SPECIAL STUDENTS. 

George F. Metzlee, Ph.D., Honorary Fellow in Psychology, 1891-92. 
Calvin H. Andeews, Mathematics and Pedagogy, 1894-95. 
Walter E. Andeews, Mathematics and Pedagogy, 1894-95. 



Whole number of students in mathematics in 10 years 44 

Aggregate attendance (including 4 who remain in 1899-1900) ... 83 years. 

Average number of students per year 8 

Average attendance per student 2 years. 



Mathematics. 63 

Mathematics occupies a peculiar position relatively to the arts and 
sciences. It is, par excellence, an art, inasmuch as its chief function 
is to solve problems, — not such examples as are given in the text-books, 
and which serve only as exercises in the application of methods, but any 
problems that may arise in human experience and for whose correct solu- 
tion sufficient data are at hand. When any line of investigation, to 
whatever subject it may refer, has been carried so far that exact reason- 
ing may be applied to it, mathematics is the authority to which the 
results of observation are submitted for the final determination of their 
consistency and the conclusions that may be drawn from them, and fur- 
nishes the means of applying these conclusions to the prediction of phe- 
nomena not yet observed. No science and no branch of technology is 
exact, that is, capable of predicting with certainty what will happen 
under given conditions, unless it rests upon a mathematical foundation. 
Astronomy, physics, and applied mechanics already have this foundation 
to a considerable extent, while the other sciences are still in the inductive 
stage, in which material is being collected with which, it is to be hoped, 
such foundation will ultimately be laid. Mathematics is also a science, 
inasmuch as it has accumulated a large body of systematic knowledge 
involving and leading to the methods that it employs in its solutions. 
These methods are of such a peculiar nature, differing so widely from 
other methods, that a special course of training is requisite if any one 
would learn to use them, and their number and variety have become so 
great that a lifetime would not suffice to acquire familiarity with them 
all. But new problems are continually arising and demanding new 
methods, and we need, therefore, a body of men who shall devote them- 
selves especially to the task of supplying this demand. While the col- 
leges are engaged in general liberal education, teaching a variety of 
subjects that develop the mental faculties (and no subject is more effi- 
cient than mathematics for this purpose) and make the student acquainted 
with his own tastes and powers, thus enabling him to determine the life- 
work for which he is best fitted, it is the special function of the university 
to extend the limits of human knowledge, and to train those who have 
unusual intellectual talents to employ them to the best advantage. We 
believe this object is best accomplished by an institution devoted solely 
to it, and whose teachers' energies are not diverted by the lower, though 
no less important, aims of the college. 

When the policy that should characterize this University was under 



64 Department of 

discussion, the first point decided was that its work should be strictly 
post-graduate, and that it should not compete with other institutions 
in the work that is generally recognized as undergraduate. In accordance 
with this principle, the mathematical department fixed its standard of 
admission so as to require such a knowledge of mathematics as can be 
obtained in the average American college, and laid out upon this foun- 
dation a curriculum of its own, as extensive and as thorough as circum- 
stances allowed. In elaborating the details of this curriculum, we have 
kept in mind the fact that those who pursue post-graduate studies in 
pure mathematics almost always look forward to careers as professors 
in colleges or other higher institutions of learning ; and we have taken 
the view that, other things being equal, the ideal teacher is a master 
of his subject, not only conversant with the general principles of all its 
more important branches, the problems that have arisen in each, the 
methods that have been devised for the solution of these problems, and 
the results that have been obtained, but also unbiassed, ready and sound 
in judgment, and actively engaged in scientific research. We believe 
that the training that is best adapted to produce efficient specialists is 
also the training that is best adapted to produce efficient teachers of 
specialties. 

While desirous of supplying all possible facilities to those who wish to 
pursue studies in special branches, and to those who, already occupying 
permanent positions, have but a limited leave of absence, we have made 
it our chief object to provide a thorough training for those who, having 
just completed a college course, have not yet entered upon their life-work. 
This provision consists of such courses of lectiires, seminaries, and indi- 
vidual assistance as should enable a faithful student endowed with the 
proper natural ability to satisfy the requirements for the degree of Doctor 
of Philosophy at the end of his third year with us. The requirements 
for this degree have been determined by our conception of the ideal 
teacher, as already stated. To acquire the necessary breadth of knowl- 
edge of mathematics as a whole, the candidate is expected to attend, 
during his first two years, specified courses of lectures on the general 
principles, methods, and results of all the more important branches of 
pure mathematics, to supplement these lectures by private reading, and to 
take an active part in the seminary. In the seminary, a special topic, 
more or less directly connected with the subject of some lecture, is as- 
signed, from time to time, to each student, who is required to read it up 



Mathematics. 65 

and make an oral report upon it before the class. Advanced courses of 
lectures on special subjects that vary from year to year are also given, 
and each candidate for the degree is expected to attend a number of such 
courses. The student spends the greater part of his third year in the 
original investigation, under the constant personal guidance of one of the 
instructors, of a topic of his own selection. In preparing for this inves- 
tigation, he is required to make a practically complete bibliography of the 
subject, and to read all the more important available articles that have 
been written on it. The results of the investigation, embodied in a dis- 
sertation suitable for printing, must be submitted to the instructor under 
whose direction the work was done, and must receive his approval before 
the candidate will be admitted to the final examination for the degree. 
This approval will not be given unless the dissertation is satisfactory in 
form and completeness and the results are sufficiently novel and impor- 
tant to constitute a real contribution to science. The dissertation is, in 
fact, the main criterion by which the candidate is judged, and no amount 
of other work will compensate for its defects. The ability of our grad- 
uates to carry on research and the excellence of the work actually done 
is assured by the regulation that each dissertation accepted by us as 
worthy of the degree shall be printed with the explicit approval of a 
member of our Faculty. It is evident that, whereas any one that has the 
necessary preparation and taste for mathematics may profit by the advan- 
tages here afforded, only those who have a certain amount of mathematical 
genius can secure the degree. 

In making appointments to fellowships and scholarships we have 
endeavored to maintain the same high standard. We are on the lookout 
for mathematical geniuses ; but it is difficult to determine from the evi- 
dence of others whether candidates come up to our standard or not ; so 
that we have adopted the general policy of giving the best appointments 
to those only that have been with us for at least one year, and about 
whom we are in position to judge for ourselves. Of course, this policy 
could not be carried out during the earlier years of the University, and 
its effect is apparent in the fact that, whereas seventy-five per cent of the 
students that entered the mathematical department during the first three 
years remained with us but one year, only twenty per cent of those that 
have been admitted during the last seven years left at the end of their 
first year. I do not mean to imply that those who left before completing 
our course were inferior in ability to those who remained three years, but 



66 Department of 

we desire particularly to encourage men who can and will go forward to 
the degree. 

Nearly all of those who have studied mathematics with us have 
adopted teaching as a profession, two-thirds are now members of college 
faculties, and one-third are engaged in higher school work. Those who 
have received the doctor's degree have generally secured at once desir- 
able positions in which to begin their life-work, and most of them have 
already acquired for themselves, by distinguished ability, very decided 
influence in the institutions with which they are connected. Of those 
who have left without the degree fully one-half ought to hSve continued, 
and would have done so but for want of pecuniary means ; and we have 
been obliged to turn away many men of very great promise on account of 
our inability to assist them in providing the means of subsistence during 
the unproductive period of student life. We could employ for fellow- 
ships, with decided advantage, ten times the amount now at our disposal. 

Although, as I believe, students will find here a broader post-graduate 
curriculum in mathematics and greater personal attention from the in- 
structors than at any other university in the country, we need greater 
facilities to make our course what it ought to be. Four-fifths of the in- 
struction in the department is now given by two men, and we are com- 
pelled to give in alternate years lectures on fundamental subjects that 
ought to be given every year. As I have said, we lay great stress upon 
the ability of our students to investigate ; but this faculty can be fully 
developed only under the personal guidance of one who is himself in the 
habit of investigating and who has the facilities and opportunities neces- 
sary for such work. A teacher's usefulness is greatly increased by the 
inspiration that comes from a personal identification with his subject, 
from the fact that he has ideas of his own about it, and that he has ex- 
tended it by his individual exertions ; and the investigator can have no 
greater incentive to search for new results than the opportunity to pre- 
sent his thoughts and discoveries to an intelligent and appreciative class 
in the lecture-room. But the necessity of teaching many subjects simul- 
taneously distracts the mind and is fatal to research. The ideal condi- 
tions for an instructor in an institution like this would be those under 
which he could teach one subject at a time, and that a subject that he 
was himself developing, and follow this subject with his class to such 
a point as to bring into evidence the scope and importance of his own 
work. To apply this method to the courses that are actually given here 



Mathematics. 67 

woiild require the services of three additional instructors in mathematics. 
We are actually laboring under the disadvantage that some of the im- 
portant branches now taught by us are not of such paramount interest 
to any one of our instructors as to be the subject of his personal investi- 
gation. We are compelled to restrict ourselves to elementary courses in 
many branches that ought to be carried to a much higher point, and to 
omit altogether from our consideration applications of mathematics to 
statistics, to the arts, and to other sciences. Applications to physics re- 
ceive the attention of the physical department, to be sure, but the mathe- 
matical department ought to do much more than it is at present able to 
do in preparing students for higher work in physics. The number of 
instructors necessary for such advanced work as we do is not to be deter- 
mined by the number of our students, but by the number of subjects 
taught. 

Again, every expert investigator finds himself continually obliged to 
spend much time in details that could just as well be worked out by a 
younger man, to whom such work would be of immense advantage, not 
only as an exercise in the practical application of methods, but also as 
furnishing the opportimity for a prolonged study of the workings of an 
investigator's mind ; and example is worth more than precept in the 
development of the faculty of investigation. We ought to have the 
means of retaining our best graduates for a year or two as personal assist- 
ants to the instructors, during which period they might also be gaining 
experience in the class-room by teaching a few hours a week under the 
supervision of one of the regular instructors. Such work is not drudgery, 
and would be, I think, sufficiently attractive to an ambitious young man 
to induce him to remain with us on a moderate stipend while he is wait- 
ing for such appointment as may seem to him desirable. 

It is almost universally assumed that a mathematician needs no mate- 
rial equipment other than brains, with, possibly, a few books. However 
true this assumption may have been some decades ago, — and I fancy that 
its truth then rested solely upon the difficulty of procuring such equip- 
ment, — it is not true now, as must be apparent to any one who studied 
carefully the German educational exhibit at the World's Fair in Chicago. 
Ten years ago our department started out with a fair nucleus for a 
mathematical library and a moderate collection of models, to which we 
have not been able to make many additions. We have very few of the 
older mathematical works that illustrate the history of the subject, and 



68 Department of 

we need particularly complete sets of many important mathematical jour- 
nals and the transactions of learned societies. In these journals and 
transactions have appeared most of the original investigations to which, 
as investigators ourselves, we have continual occasion to refer, both for 
suggestions and to avoid apparent plagiarism and the unnecessary dupli- 
cation of research. We should also be greatly assisted in our class-work 
by a more complete collection of models. 

In short, what I have in mind as a model mathematical department 
for post-graduate work would have, say, four professors and assistant 
professors, each having his personal assistant, and at least two instructors 
of lower grade for the more elementary work, and would be provided 
with a complete mathematical library and with all the apparatus that it 
is now possible to procure, with suitable provision for the purchase of 
new books and apparatus as they appear in the market. 

These schemes are not incapable of realization, although, perhaps, 
opposed to the traditions of education in this country. This University 
has never had any traditions excepting such as were based upon high 
ideals. Its mathematical department was not modelled after that of any 
other institution, but was determined by the conception of what would 
constitute perfection in such a department. We have always lived up to 
our ideals, in so far as we have done anything, without regard to consid- 
erations of material interest. We are not here to do what is done else- 
where, and we do not acknowledge that it would be best for us to do what 
other institutions, in their experience, have thought wisest. We propose 
to adopt no temporary policy that we shall sometime want to abandon, 
confident that the ideal university of the future will be ideal from the 
very root and not a graft upon inferior stock. 

When the doors of the Universty were first opened to students, in the 
fall of 1889, the mathematical staff consisted of William E. Story, Pro- 
fessor, Oskar Bolza, Associate, and Henry Taber, Docent ; a year later it 
was increased by the appointment of Joseph de Perott, Docent, and 
Henry S. White, Assistant ; and in 1892 Drs. Bolza and White resigned 
their positions to accept Associate Professorships in the University of 
Clucago and Northwestern University, respectively, and Dr. Taber was 
promoted to an Assistant Professorship, thus leaving the department with 
practically the same teaching force as it had during the first year. 

The instruction has been given by lectures, seminaries, and individual 
conferences. The number of lectures (of fifty minutes each) was sixteen 



Mathematics. 69 

a week the first year, nineteen and twenty a week in the second and 
third years, respectively, and about fourteen a week, on the average, each 
year since. In some years courses of lectures on certain mathematical 
subjects having important physical applications have been given by 
Assistant Professor Webster of the Department of Physics. 

The subjects of the lecture courses given during the ten years include 
the following : — 

1. The History of Arithmetic and Algebra among various peoples from the 
earliest times to 1650 a.d. 

2. Theory of Numbers (introductory). 

3. Theory of Numbers (advanced). 

4. Nmaerical Computations. 

6. Theory of Quadratic Forms. 

6. Finite Differences. 

7. Probabilities. 

8. Theory of Errors and the Method of Least Squares. 

9. Theory of Functions of a Real Variable. 

10. Linear Transformations and Algebraic Invariants (introductory). 

11. Theory of Substitutions, with applications to algebraic equations (intro- 
ductory). 

12. Theory of Transformation Groups. 

13. The Application of Transformation Groups to Differential Equations. 

14. Finite Continuous Groups. 

15. Klein's Icosahedron Theory. 

16. Simultaneous Equations, including Restricted Systems. 

17. Theory of Functions of a Complex Variable, according to Cauchy, Eie- 
mann, and Weierstrass (introductory). 

18. Definite Integrals and Fourier's Series (introductory). 

19. Ordinary Differential Equations (introductory). 

20. Ordinary Differential Equations (advanced). 

21. Partial Differential Equations (introductory). 

22. Elliptic Functions, according to Legendre and Jacobi (introductory). 

23. Weierstrass's Theory of Elliptic Functions. 

24. Elliptic Modular Functions. 

25. Abelian Functions and Integrals. 

26. Theta-Functions of Three and Four Variables. 

27. Eiemann's Theory of Hyperelliptic Integrals. 

28. Eiemann's Surfaces and Abelian Integrals. 

29. Conic Sections by modern analytic methods (introductory). 

30. Quadric Surfaces by modern analytic methods (introductory). 

31. General Theory of Higher Plane Curves (introductory). 

32. Plane Curves of the Third and Fourth Orders. 



70 Department of 

33. General Theory of Surfaces and Twisted Curves (introductory). 

34. Surfaces of the Third and Fourth Orders. 

35. Twisted Curves and Developable Surfaces (advanced). 

36. Applications of the Infinitesimal Calculus to the Theory of Surfaces. 

37. Rational and Uniform Transformations of Curves and Surfaces. 

38. Enumerative Geometry. 

39. Analysis Situs. 

40. Hyperspace and Non-Euclidean Geometry. 

41. Modern Synthetic Geometry (introductory). 

42. Quaternions, with applications to geometry and mechanics. 

43. Multiple Algebra, including matrices, quaternions, " Ausdehnungslehre," 
and extensive algebra in general. 

44. Symbolic Logic. 

Courses designated as " introductory " are given at least as often as 
every other year, and attendance on them is required of all candidates 
for the degree of Doctor of Philosophy that take mathematics as their 
principal subject. The other courses, intended primarily for the more 
advanced students, have been given less frequently and with particular 
reference to the suggestion of topics for original investigation. 

In connection with his lectures, Assistant Professor Taber has con- 
ducted a weekly seminary for students in their first or second year, for 
the purpose of cultivating in them an active attitude toward the subjects 
treated, instead of the passive attitude usually resulting from hearing 
lectures. Topics related to those of the lectures have been discussed 
by the students, and their work has been criticised both with reference 
to rigor of demonstration and manner of presentation. In this way some 
of the advantages of the laboratory and the practice school are brought 
into the field of mathematics. Professor Story, with the assistance of 
the other instructors, has directed the more advanced students individ- 
ually in the systematic investigation of special topics that promised to 
afford opportunity for the discovery of new results and methods, — a task 
that has sometimes required the professor to hold weekly three-hour 
conferences with each of four students during nearly the entire academic 
year ; but we believe the results have justified this unusual expenditure 
of energy. 

The average annual number of students taking mathematics as their 
chief study has been about eight, the average duration of their residence 
was about two years, and more than one-third of them have received (or will 
undoubtedly receive) the Doctor's degree, which is a decided improve- 



Mathematics. 71 

ment in every respect over the record of the first three years. The pub- 
lished investigations of these students are enumerated in the Bibliography 
at the end of this volume. 



The researches of an instructor in an institution of this kind are not 
to be judged solely by the number and magnitude of his printed papers, 
as many, of them are naturally turned over, in a more or less incom- 
plete form, to his pupils for further investigation and more adequate 
presentation ; at least it seems most natui-al and desirable that an in- 
structor should suggest to his pupils subjects for investigation on which 
he has himself worked, and for whose treatment he has found adequate 
methods. 

My chief subjects of investigation have been : — 

1. Hyperspace and Non-Euclidean Geometry. 

2. Algebraic Invariants. 

3. Curves on Euled Surfaces, and Restricted Equations. 

4. The History of Mathematics prior to the invention of the infinitesimal 
calculus, and 

5. A Mathematical Cui-riciUum for Primary and Secondary Schools. 

I have developed systematically the general theory of space of any 
number of dimensions from assumptions that are precisely analogous to 
those on which the scientific treatment of threefold space is usually based, 
and wliich we recognize as the results of experience. In accordance with 
this general theory, I have thoroughly investigated the properties of loci 
of the first and second orders and some special loci of higher orders. 
The introduction of the most general kind of measurement has then led 
me to an equally thorough study of parallel and perpendicular loci, the 
curvature of loci, areas, and volxmies in the most extended sense. The 
first part of these results has already appeared in the Mathematical 
Review, and I hope to publish the remainder within a short time. 

Ever since the appearance of Clebsch's "Theorie der binaeren alge- 
braischen Formen," toward the end of the year 1871, when I was study- 
ing in Berlin, I have taken a lively interest in the theory of algebraic 
invariants, — - an interest that was greatly augmented by my association 
with Sylvester at the Johns Hopkins University in 1876. I had thought 
all along that there ought to be a direct process by which all such invar 



72 Department of 

riants could be obtained, but my efforts to find it had failed. A course 
of lectures on invariants that I have given every year or two since the 
opening of Clark University caused me to renew my attempts, and the 
classic paper of Hilbert in the 36th volume of the Mathematisohe 
Annalen, in which a process devised by Mertens (and which I regarded 
as indirect, inasmuch as it involved quantities extraneous to the matter 
in question) suggested a new line of research, which happily led at length 
to the long-sought direct process. I then applied this process, as Hilbert 
had applied Mertens's process, to the proof of Gordon's theorem that aU 
the invariants of any finite system of quantics of finite orders can be 
expressed rationally in terms of a finite number of such invariants. 
These results were published in the Mathematisohe Annalen and in the 
Proceedings of the London Mathematical Society. I have spent much time 
in trying to find, by means of the process, an extension of Cayley's for- 
mula for the number of linearly independent ground-forms of a single 
binary quantic (extended by Sylvester to any system of binary quantics) 
to the case of quantics involving three or more variables, but so far with- 
out success. 

In my lectures on surfaces of higher orders and twisted curves I have 
paid particular attention to the algebraic curves that lie upon a given 
algebraic surface. If the given surface is ruled, the curves on it can be 
classified in such a way that certain problems relating to a curve can be 
solved when the class of the curve is known. My investigations in tliis 
direction have been communicated to my students, some of whom have 
already solved such problems. In connection with my investigations on 
twisted curves, I have also made a systematic study of restricted equa- 
tions, and have carried the determination of the orders of such systems 
much farther than had been done before. 

I have lectured at various times on the early history of mathematics, 
with special reference to the development of arithmetical and algebraic 
symbolism, and have collected a large number of systems of siich symbols, 
which I hope sometime to utilize for a monograph on the subject. 

In connection with a course of lectures delivered for two years at the 
Summer School, I arranged a mathematical curriculum for primary and 
secondary schools, which will be published when I can find the leisure 
necessary to prepare the explanatory text. 

At my request. Assistant Professor Taber has furnished the material 
for an account of his personal researches, which involves such a complete 



Mathematics. 73 

and excellent history of the theory of matrices that it seems to me inad- 
visable to abbreviate it ; I therefore append it to this report at length, for 
the benefit of those readers who may be interested in the subject. 



Dr. Taber's researches have been devoted to the development of the 
theory of matrices, and its application to bilinear forms', multiple algebra, 
and theory of finite continuous groups. The calculus or theory of matrices 
was invented by Professor Cayley (see his " Memoir on the Theory of 
Matrices," Phil. Trans., 1858), and has proved an instrument of great 
power in the theory of linear transformation, bilinear forms, and for the 
investigation, generally, of the projective group. ^ In order to explain 
the work done by Dr. Taber in this direction, a few words of explanation 
will be necessary to describe the work done by Cayley and others. 

Associated with any linear substitution 



c/ = > afjXj (i = 1, 2, ••• n) 



is the bilinear form A = y y o^^x^yj, which may be regarded as repre- 
senting this substitution, or vice, versa ; and, in the theory of matrices, we 
do not need to distinguish between this linear substitution and the asso- 
ciated bilinear form, or between either and the matrix 



iij = 1, 2, ••■ w 

common to both. If now B denotes the bilinear form y y ^ijX^}i or 

its associated linear substitution, A± B will denote the bilinear form 

/ / (*u + ^v)^iyj'< or its associated linear transformation ; and AB 

will denote the bilinear form / ^/ ^.[/ ^ <^n^n j^i^ji or its associated 

linear substitution (obtained by the composition of the linear substitutions 
A and 5). Equivalence between two bilinear forms or linear substitu- 

1 By means of this calculus very important results have been ohtained by Cayley himself, 
by Sylvester, Frobenius, Foss, Weyer, Study, and others ; and, by methods essentially simi- 
lar, Kronecker obtained important theorems on the orthogonal group to v^hich reference is 
made below. 



74 Department of 

tions, A and B, is denoted by writing A = B. Further, in what follows, 

I will denote the identical transformation, represented by ^.a?i2/i, and 

1 
A-^ the form, or substitution, satisfying the symbolic equation AA-^ 

= A-^A = I; A will denote the bilinear form 7 7 «,i«,%-5 transverse 

or conjugate to ^ = > > ^'ipiUii and \A\ will denote the determinant 

1 ' I '' 
of the matrix A. A is said to be symmetric if J. = J., and alternate, or 

skew symmetric, if A = — A.^ 

Cayley was, perhaps, led to the invention of this calculus by his 
researches upon orthogonal substitution, Orelle (1846), Vol. 32. For 
in Crelle, Vol. 50, three years before the publication of his memoir on 
matrices, he expressed the results of these researches in the notation of 
matrices. Thus Cayley showed that the general expression for the proper 
orthogonal substitution in n variables is (Z— -B)(J+ 5)-S where B 
denotes an arbitrary alternate, or skew symmetric, linear substitution; 
and this expression gives Cayley's determination of the coefficients of a 
proper orthogonal substitution in n variables as rational functions of the 
essential parameters, ^n(n — V) in number. 

Again, in his " Memoir on the Automorphic Linear Transformation of 
a Bipartite Quadrate Function" (PA^7. Trans., 1858), Cayley showed that 
the general automorphic linear transformation (linear transformation into 

itself) of a symmetric (alternate) bilinear form ^ = / / .«y<Ci^j with 

1 1 
cogredient variables and of non-zero determinant, may be represented by 

(J. + Xy~^QA — X}, where X is an arbitrary alternate (symmetric) bi- 
linear form. This expression gives in the first case (when A is symmet- 
ric) Hermite's determination of the general proper automorphic linear 
transformation of a symmetric bilinear form, and, in the second case 
(when A is alternate), Cayley's determination of the transformation into 
itself of an alternate bilinear form. Further, in this same memoir Cay- 
ley showed how to reduce, to the solution of a system of n^ linear equa- 
tions, the rational determination of the •n? coefficients of the automorphic 
linear transformation of a general bilinear form A (neither symmetric 
nor alternate) with cogredient variables and of non-zero determinant. 
Namely, he showed that the general formula for such a substitution is 

J- In the first case uji = ay, in the second ajt = — ay (i, j = 1, 2, ••• n). 



Mathematics. 75 

{A + X)-^ (A-X), where X satisfies the condition (A)-^X+ A-^X = 0. 
This result includes the determination of the general automorphic trans- 
formation of A, when A is symmetric and when A is alternate. It also 
includes Cayley's determination of the coefficients of an orthogonal substi- 
tution to which it reduces when A = I. 

In what follows Cr will denote the group of proper automorphic linear 
transformations of A (the x's and y's being cogredient), and Gr' the proper 
orthogonal group. A transformation T oi G- (or of 6r') is termed singular 
if —1 is a root of its characteristic equation (namely, | T— pl\ =0); 
otherwise, non- singular. Every non-singular transformation of group Gr 
(or <7') is given by Cayley's formula, and may be termed a Cayleyan 
transformation of the group. ^ No singular transformation of group G is 
given by Cayley's expression or determination. But for A alternate, also 
when A is neither sjrmmetric nor alternate provided | J[ ± J. | =?i= 0, Dr. 
Taber showed in 1894 (^Proc. Am. Acad. Arts and Sciences, Vol. 29) that 
group Cr is generated by the Cayleyan transformations of the group, — 
each transformation T of this group being obtained by the composition of 
a finite number of Cayleyan transformations. In the same paper Dr. Taber 
also showed that the sub-group of orthogonal transformations of Q is, 
similarly, generated by the non-singular orthogonal transformations of 
this sub-group, when A is alternate, and when A 4= ± A provided 
|i± ^ I ^ 0. 

This theorem is similar to a theorem relating to the orthogonal group 
(group (r') established by Kronecker in 1890 (" Ueber orthogonale Sys- 
teme," Sitzungsberich. d. Preuss. Akad.'), who showed that this group 
is generated by the Cayleyan transformations of the group, each trans- 
formation T of this group being obtained by the composition of two 
Cayleyan transformations, — the coefficients of each of the Cayleyan 
transformations being rational functions of the coefficients of T. 

In 1895 (Math. Ann., Vol. 46) Dr. Taber showed that, if A is real and 
alternate, every real transformation T oi G can be obtained by the com- 
position of two real Cayleyan transformations of this group. This 
theorem was obtained independently and extended widely by Dr. Loewy, 
who in 1896 (^Math. Ann., Vol. 48) showed that, if A is irreducible 

1 For the case in which A is symmetric, the determination of the coeflBcients of T, given 
by Cayley's formula, is properly Hermite's ; but it is not convenient to distinguish here 
between this case and the other two cases, namely, when A is alternate, or is neither 
symmetric nor alternate, when the determination is Cayley's. 



76 Department of 

(which case includes that in which A is alternate), every transformation 
of Cr, real or imaginary, can be obtained by the composition of two 
Cayleyan transformations of the group, and that, therefore, when A is 
irreducible, there is no transformation of the kind termed by Foss 
essentially singular,^ that is to say, which cannot be obtained by the com- 
position of two non-singular, or Cayleyan, transformations. 

For a reducible form A not every singular transformation of (7 can be 
obtained by the composition of two Cayleyan transformations of this 
group. Nevertheless, Dr. Taber showed in 1897 (^Math. Review, Vol. 1) 
that in every case the Cayleyan transformations of Cr form a group by 
themselves ; that the composition of any number of Cayleyan transforma- 
tions of Cr results in a transformation that can be obtained by the 
composition of two Cayleyan transformations of this group; and that thus 
the composition of Cayleyan transformations never gives rise to an 
essentially singular transformation. 

It is to be noted that from Cayley's formula for a transformation T of 
Cr, namely, 

T= {A + Xy (A-X} = (J- ^-'X)(7-f- A-'X}-\ 

we derive X=A(1 - T)(l + T)-"^; 

and, therefore, the parameters, namely, the coefficients of X, which enter 
into the determination of T, can be expressed rationally in the coefficients 
of T and of A.^ Similarly, in the memoir by Kronecker mentioned above, 
he has shown that the coefficients of the two Cayleyan transformations, 
whose composition gives the general transformation T of group Cr', can be 
expressed rationally in the coefficients of T. For A real, alternate, and 
orthogonal, Dr. Taber gave, in the paper in the Mathematische Annalen 
mentioned above, the determination of the coefficients of the two Cayleyan 
transformations G^ and Cj, whose composition gives any real transforma- 
tion T of (?, as rational functions of the coefficients of T and of A. This 
determination of (7j and (Jg he has since extended to the case in which T 
is imaginary, and A any alternate bilinear form.^ 

Dr. Taber has pointed out that the transformations of Cr, both when 
A is irreducible and when A is reducible, are in general of two essentially 

'^Ahhand. d. k. Bayer. Akad. d. Wiss., 11. CI., XVII. Bd., II. Abth. 1890, p. 77. 
2 Between these parameters when A is neither symmetric nor alternate n^ equations 
persist. 

5 See papers to appear in Proc. Am. Acad, of Arts and Sciences, Vol. 35. 



Mathematics. 77 

different kinds. The difference between the two kinds of transformations 
of Gr is given by the following theorem : — 

(I.) If we designate a transformation of group G as of the first or sec- 
ond kind according as it is or is not the second power of a transformation 
of the group, then every transformation of the first kind is the vcdh power 
of a transformation of the group, for any positive integer m, and can he 
generated hy the repetition of an infinitesimal transformation of the group. 
A transformation of the second kind, by definition not an even power of any 
transformation of the group, is always the (2m + 1)"" power of a transforma- 
tion of the group for any odd exponent 2m + 1. But no transformation of 
the second kind can he generated by an infinitesimal transformation of the 
group. " 

(II.) Every Cayleyan transformation of group G is a transformation 
of the first kind ; whereas, a non- Cayleyan transformation is, in general, of 
the second kind.^ 

Dr. Taber has also given the conditions necessary and sufficient that 
a transformation T of group Gr may be of the first kind for the case in 
which A is symmetric (which includes the case when A = I, in which case 
6r becomes &'}, and for the case when A is alternate.^ 

Dr. Taber has shown that, if A is neither symmetric nor alternate and 

^ This was proved for the orthogonal group in 1894, Bull. Am. Math. Sac, Vol. 3. At 
the conclusion of this paper it was stated that a precisely similar theorem held for what 
is here designated as group O. In the Math. Ann., 1895, Vol. 46, the theorem was proved 
for group G when A is alternate ; for the case in which A is symmetric, in the Proc. 
Land. Math. Sac, 1895, Vol. 26; and for the general case, in the Math. Seview, 1897, 
Vol. 1. 

2 For the orthogonal group, to which G reduces when A = I, the conditions necessary and 
sufficient that a transformation shall be of the first kind were given by Dr. Taber in a com- 
munication to the American Academy of Arts and Sciences, March, 1895. (See Proceedings, 
Vol. 30, p. 551.) The necessity and sufficiency of these conditions was afterwards shown in 
Proc. Land. Math. Soc, 1895, Vol. 26, and the theory for the orthogonal group extended 
to group G for A symmetric. It was not explicitly stated in this paper that the conditions 
given for the orthogonal group hold for G when A is symmetric, being so obvious a conse- 
quence of the considerations adduced. This does not seem to have been recognized by Dr. 
Iioewy, who refers to this paper but gives the necessary and sufficient conditions, Math. 
Ann., Vol. 48, when A is symmetric as an extension of Dr. Taber's theorem for group G'. 

For A alternate the necessary and sufficient conditions were given by Dr. Taber in a 
communication to the American Academy of Arts and Sciences, January, 1896. (See Pro- 
ceedings, Vol. 31, p. 349.) The necessity of these conditions has previously been shown by 
Dr. Taber in the Math. Ann., Vol. 46. In Vol. 49 (1897), Dr. Loewy gave the conditions as 
sufficient, undoubtedly without knowledge of Dr. Taber's priority in the statement of 
this theorem. 



78 Department of 

\A±A\^(i, group Cr contains no transformation of the second kind. TMa 
theorem leads, for the case mentioned, to the following rational represen- 
tation of any transformation of this group, namely, 

where (^A')~'^ X + A~^ X = 0. Moreover, Dr. Taber has shown that the 
sub-group of orthogonal transformations of Cr contains no transformation 
of the second kind when A is alternate.^ 

The determination of the congruent transformations between two bi- 
linear forms is the natural generalization of the problem to determine the 
automorphic linear transformations of A. A determination of the trans- 
formations between A and B depending on the solution of a single equa- 
tion of degree n has been given by Dr. Taber (^Mathematical Review, Vol. 
1, 1897), which holds for any case whatever in which A and B are both 
symmetric or both alternate. 

The theory of matrices, or bilinear forms, is closely related to the 
theory of Hamilton's linear vector functions. In the American Journal 
of Mathematics, Vol. 12, Dr. Taber has given a development of the 
theory of matrices, proving many of the fundamental theorems, from the 
point of view of Hamilton's theory. 

One of Sylvester's most important contributions to the theory of 
matrices was a general formula, given in the Comptes Bendus, Vol. 94, 1882, 
expressing any power, integral or fractional, of the bUinear form or matrix 
A&s & polynomial in J. of degree w — 1. Thus, if 5 = J.'', where fi is any 
fraction, and if p^, p^, . . . p^ are the roots of the characteristic equation 
of A, we have 

£ ^ 2p^ (^ - PJX^ - Pa-?") - (^ - Pnl) 

' (.Pl-p2)(.Pl-Ps)-(.Pl-Pn) 

By means of this theorem the determination of a matrix or linear substi- 
tution whose fith power is equivalent to A is reduced to the solution of a 
single algebraic equation of degree n. This formula was afterwards ex- 
tended by Sylvester to any function of the matrix A.^ Thus we have 

/(A) = s/(p,) C-4.-P./)y-P3^)-(^-P.J) . 

(.Pi - P2)(.Pl - ft) - (.Pi - PrJ 

1 See Bull. Am. Math. Soc, Series 2, Vol. 2, pp. 5 and 161. 
* Johns Hopkins Univ. Circulars, No. 28, Vol. 3, p. 34. 



Mathematics. 79 

Neither of these formulae applies unless the roots of the characteristic 
equation of A are all distinct. For the general case, in which the roots 
of the characteristic equation have any given multiplicities, a formula for 
/(J.) has been given by Dr. Taber.i Thus, if the distinct roots of the 
characteristic equation are /Jj, p^, ••■ p„ respectively of multiplicity m^, m^, 
■••m„ and if J.<'> = A^^^'^ ...^,_iC'^i+i<'' -A^^'^ where 4« denotes 

ICA - pJYi - (pj - p^rd^J : [( - ITKPj - ft)'"'"'^], 
then 



rp=o. 



For wij = ^2 = ••• wi;. = 1, this reduces to Sylvester's formula. 

The theory of matrices stands in a very special and important relation 
to the theory of higher complex quantity (multiple algebra). Namely, a 
class of systems of complex numbers with ti^ units arises from the theory 
of lineal transformation, — that is to say, a matrix of n^ elements gives 
rise to a system of n^ units e^- with the special multiplication table e^ ej^ — 
^iki ^ii «H = ioTJ =^ k. Multiple algebras (systems of complex numbers) 
of this class have been termed by Mr. Charles S. Peirce quadrate alge- 
bras, or quadrates ; and Peirce has shown that the p units of any system 
of complex numbers (the p units of any multiple algebra) can be expressed 
linearly in terms of the rt? units of a quadrate.^ Whence it follows that 
the theory of any system of complex numbers is identical with the theory 
of the combination by multiplication, addition, and subtraction, of a 
certain system of p matrices. 

The first quadrate algebra, namely, that with four units, is identical with 
the quaternions with the imaginary (Hamilton's bi-quaternions), as was 
fiirst explicitly pointed out by Professor Benjamin Peirce. That is to say, 
by substituting for the original units e^ a certain system of four linearly 
independent linear functions of the four units we obtain a system of com- 
plex numbers, 1, i, j, k, which can be substituted for the original units, and 
whose multiplication table is z^ = y^ _ ^ _ _ i^ i^ =il, etc., ij = —ji = k, 
etc. Let now i'.,j', k' be a new system of quaternion unit vectors having 
the multiplication table i'2 =y'2 = ^'2 = _ 1, i'j' = —fi' = k', etc. And 
let a third system of units be formed by the combination of these two sys- 

1 Math. Ann., Vol. 46, p. 568. See also Pj-oc. Am. Acad, of Arts and Sciences, 1893, VoL 
27, p. 46 et seq. 2 See Am. Jour. Math., Vol. 4, pp. 122 and 125. 



80 Department of 

terns, it being assumed that each of the one system of quaternion unit 
vectors is commutative with each unit vector of the other system. That 
is to say, that ii' — i'i, ij' =j'i, etc. We get thus sixteen units, 1, i, j, 
k, i', j', k', and the nine binary prdducts ii', ij', etc. Dr. Taber has shown 
tliat the system of units tlius obtained is identical with the quadrate of six- 
teen units. The same is true if we had combined the four original units 
of the . quadrate with four units, namely, e„ (r, s = 1, 2) with a similar 
system of another quadrate, viz., e'„ C*"! s = 1, 2), — assuming that e„e',u 
= e't^e^s- The resultant system has sixteen units, and is the quadrate with 
sixteen units. ^ Dr. Taber has established a general theorem including 
the one just given. Namely, he has shown that, if w = mp, the quadrate of 
n^ units is a compound of two quadrates severally with m units and p units, 
the units of one quadrate system being commutative with each unit of the 
other quadrate.2 Whence it follows that if the prime factors of n are Sj, 
Sj, "-S^and n = B-^i^^B^i^^---B^ >-, the quadrate of n^ units is a compound of fi^ 
quadrates each with S^ units, /^j quadrates each with 8^ units, etc. 

The general projective group holds a position of special importance 
in Lie's theory of finite continuous groups. For the adjoined group T of 
any finite continuous group G, by means of which the sub-groups of G are 
determined, will, if the equations of transformation of this group are 
properly chosen, appear as a sub-group of the general projective group. 
Thus the theory of matrices is of importance in the investigation of 
certain problems of Lie's theory, since this calculus furnishes a convenient 
instrument for the treatment of the general projective group. 

The chief theorem of Lie's theory states that if a system of infinitesi- 
mal transformations satisfies certain conditions, they generate a group 
with continuous parameters, each of whose finite transformations can be 
generated by an infinitesimal transformation of the group. ^ In 1892 
Professor Study made the extremely important discovery that this 
theorem is subject to certain limitations, — showing that an exception to 
this theorem existed in the case of the special linear homogeneous group in 

1 Am. Jour. Math., Vol. 12, p. 391. 

^ Ibid. This theorem was obtained independently, hut subsequently, by Professor Study. 
See " Math. Papers of Internat. Math. Congress of 1893," p. 378. 

' Transformationsgruppen, Vol. 1, pp. 75, 158 ; Continuierliche Gruppen, p. 390. Lie 
originally defined a finite continuous group, substantially (Trans. &rp., p. 3), as a group with 
continuous parameters. Ultimately, he assumed that in a continuous group as thus defined 
each transformation can be generated by an infinitesimal transformation of the group (Con- 
tin. &rp., p. 379). 



Mathematics. 81 

two variables, namely, that not every transformation of this group can be 
generated by an infinitesimal transformation of the group. ^ Subsequently, 
in 1893 (^Am. Jour. Math., Vol. 16), Dr. Taber showed that the orthogonal 
group in n variables (for w ^ 4) also presents an exception to Lie's 
theorem; and in 1895 gave, in a communication to the American Academy 
of Arts and Sciences, the conditions necessary and sufficient that a proper 
orthogonal substitution may be generated by an infinitesimal orthogonal 
substitution.^ 

For n> 2 also, the special linear homogeneous group in n variables is 
continuous only in the neighborhood of the identical transformations. 
For two variables. Study gave the conditions necessary and sufficient that 
a transformation of this group may be generated by an infinitesimal trans- 
formation of this group. Dr. Taber gave, in 1896 (^Bull. Am. Math. Soc, 
Series 2, Vol. 2, p. 231), these conditions for n variables ; also the conditions 
necessary and sufficient that a transformation of the special linear homo- 
geneous group may be the with power of a transformation of this group. 
From these conditions it appears that the wth power of any transforma- 
tion of this group can be generated by an infinitesimal transformation of 
this group; and that the transformations of this group can be divided into 
as many genera as there are prime factors of n. Thus, if S is a prime 
factor of n, there are transformations of this group whose n/Sth. power, but 
no lower power, can be generated thus.^ 

Dr. Taber has shown that the following groups are not continuous, 
except in the neighborhood of the identical transformations, namely, the 
group Gr, mentioned above, for A symmetric or alternate, and in general 
when A is neither symmetric nor alternate, provided either | JL -|- ^ | or 
I J^ — J. I is equal to zero.* For all these groups the infinitesimal trans- 
formations satisfy Lie's criterion. 

Dr. Taber has also shown that the following groups are continuous, 
namely, group Gr when \A±A\=^0, the sub-group of orthogonal trans- 
formations of Gr, for A alternate, and the group of automorphic linear 

transformations of a bilinear form A=^ ^ (^a^t^ji of non-zero deter- 

minant, the x's and «/'s being contra-gredient.^ 

1 Leipsige Berichte, 1892. 

2 See ProC; Vol. 30, p. 551. This result is referred to above on p. 77. 

8 See Bull. Am. Math. Soc, Series 2, Vol. 3, p. 9. * See p. 77, note 1. 

8 See p. 77 above, also Proc. Am. Acad. Arts and Sciences, Vol. 31, p. 181. 



82 Department of 

Investigations upon the continuity of the groups in two and three 
variables have been carried on under Dr. Taber's supervision by certain 
of the students in the mathematical department. Dr. E. G. Rettger has 
investigated the continuity of all the two and three fold groups, fifty-nine 
in number, enumerated by Lie, Continuierliohe Gruppen, pp. 288 and 519 ; 
and shown that twenty-one of these groups are discontinuous.^ Mr. F. 
P. Williams has investigated the continuity of certain groups of the 
plane, not treated by Mr. Rettger; and Mr. S. E. Slocum has pointed 
out the nature of Lie's error in his demonstration of the fundamental 
theorem referred to above. ^ 

If a system of real infinitesimal transformations satisfy a modification 
of the Lieschen criterion. Lie states that they generate a real continuous 
group, that is, a group with continuous parameters, each transformation of 
which can be generated by an infinitesimal transformation of the group. 
But this theorem is subject to certain modifications. 

Dr. Taber has shown that the group of real proper orthogonal trans- 
formations is continuous; 3 also that in the groups of real transforma- 
tions enumerated below not every transformation can be generated by an 
infinitesimal transformation of the group, namely, — 

the real projective group,* 
the general and special real linear groups, 
the general and the special real linear homogeneous groups, 
the sub-group of real transformations of Cr, for A real and either 
alternate or symmetric. 

Further, that if G denotes either of the groups just enumerated, the first 
part (I) of the theorem of p. 77 holds. And he has given the con- 
ditions necessary and sufficient, for each of the first three of the groups 
just enumerated, that a transformation of this group may be generated by 
an infinitesimal transformation of this group. ^ 

Let G denote a group generated by the composition of r one-fold 

1 Froc. Am. Acad, of Arts and Sciences, Vol. S3. 

2 See papers to appear in Vol. 35 of the Proc. Am. Acad, of Arts and Sciences. 

^ Bull. Am. Math. Soc. for July, 1894. See also Proc. Am. Acad, of Arts and Sciences, 
Vol. 27, p. 163. 

* For the real projective group this was first pointed out by Professor H. B. Newson, 
Kansas Univ. Quart., 1896. 

' Bull. Am. Math. Soc, Series 2, Vol. 2, p. 228 et seq. Also Proc. Am. Acad, of Arts 
and Sciences, Vol. 31, p. 336, and Vol. 32, p. 77. 



Mathematics. 83 

groups (each containing the identical transformation), namely, Gi<^\ Gi''', 
•••Gi"'^ whose infinitesimal transformations satisfy Lie's criterion. It may 
happen that a transformation T of one (or more) of these one-fold 
groups, as G/**', combined with any transformation of another of the one- 
fold sub-groups, as G/"' (in particular with the infinitesimal transforma- 
tion of Gi'"^), results in a transformation that cannot be generated by an 
infinitesimal transformation of G. Any such transformation T, together 
with any transformation T of G that cannot be generated by an infinitesi- 
mal transformation of this group, may be termed singular; all other 
transformations of G will then be non-singular. In a paper, of which an 
abstract was read at the February meeting of the American Mathematical 
Society, 1899, Dr. Taber showed that, if G is a sub-group of the projective 
group, any singular transformation of G can always be obtained by the 
composition of two non-singular transformations of G ; and moreover 
that, if T is any singular transformation of G not generated by an infini- 
tesimal transformation of G, a transformation T^, generated by an infini- 
tesimal transformation of G, can always be found which can be made to 
approach as nearly as we please to T by taking p sufficiently small, so 
that limo_n T. = T. 



DEPAETMENT OF PHYSICS. 

By Akthur Gordon Webster. 

STAFF. 

Albert Abraham Michelson, Ph.D., Professor of Physics, 1889-92. 
Arthur Gordon Webster, Ph.D., Decent in Mathematical Physics, 1890-92 ; 
Assistant Professor of Physics, 1892-. 

FELLOWS AND SCHOLARS. 

Louis W. Austin, Scholar in Physics, 1890-91 ; Fellow, 1891-92. 

Frank K. Bailey, Scholar in Physics, 1898-99. 

William P. Boynton, Scholar in Physics, 1894-95 ; Fellow, 1895-97. 

Arthur L. Clark, Scholar in Physics, 1896-97 ; Fellow, 1897-98. 

D. Ellis Douty, Scholar in Physics, 1898-99. 

William F. Duband, Scholar in Physics, Nov. -Dec, 1889. 

Thomas W. Edmondson, Fellow in Physics, 1894-96. 

Benjamin F. Ellis, Scholar in Physics, 1892-93. 

T. Proctor Hall, Scholar in Physics, 1890-91 ; Fellow, 1891-93. 

fBENjAMiN C. HiNDE, Fellow and Assistant in Physics, 1892-93. Died Feb. 

6, 1894. 
EiCHARD J. Holland, Ph.D., Honorary Fellow in Physics, 1893-94. 
James Edmund Ives, Scholar in Physics, 1897-98 ; Fellow, 1898-. 
Sidney J. Lochner, Scholar in Physics, 1892-93. 
Alexander McAdie, Fellow in Physics, 1889-90. 
Alfred G. Mayer, Assistant in Physics, 1889-90. 
Holla E. Eamsey, Scholar in Physics, 1898-99. 
Stanley H. Eood, Scholar in Physics, 1893-94. 

tCLABENCE A. Saunders, Fellow in Physics, 1892-95. Died Dec. 19, 1898. 
Benjamin F. Sharpe, Fellow in Physics, 1894-96 ; 1897-98. 
EoBERT E. Tatnall, Ph.D., Honorary Fellow in Physics, 1897-98. 
Samuel N. Taylor, Fellow in Physics, 1893-96. 

Frank L. 0. Wadsworth, Fellow in Physics, 1889-90; Assistant, 1890-92. 
Arthur J. Warner, Scholar in Physics, 1889-90. 
Albert P. Wills, Scholar in Physics, 1894-95 ; Fellow, 1895-97. 

85 



86 Department of 



SPECIAL STUDENTS. 



Eevin W. Howard, 1892-93. 
Albert B. Kimball, 1893-94. 
William Nelson, 1892-93. 
Joseph 0. Phelon, 1892-93. 



Arthur L. Eice, 1892-93. 
Stanley H. Eood, 1892-93. 
Clayton 0. Smith, 1892-93. 
Hugh M. Southgatb, 1892-93. 



The work of a Department of Physics in a university at the present 
time may be best understood after a brief survey of some of the chief 
achievements of the science during the present century. As we in this 
country have our attention called more frequently to the achievements of 
applied than to those of pure science, it is worth while to dwell somewhat 
upon the influence of pure science upon applied, and upon its contribution 
to the progress of civilization. At the beginning of the century, the 
various subjects that together make up the science of Physics were in a 
very imperfect state. Of heat, light, sound, electricity, and magnetism, 
little that we now accept was known, while of that little still less had 
been applied to practical matters. The science of mechanics, upon which 
the whole superstructure of physics must inevitably rest, had indeed been 
set upon a firm basis by the immortal Newton, while its principles had 
recently been formulated by the distinguished mathematician Lagrange, 
in a way so broad and powerful that it has not since been improved upon. 
The science of pure mathematics had of course arrived at a high degree 
of perfection, and many of the leading mathematicians had devoted their 
best efforts to the subject of mechanics. But while a large number of 
investigators had laid the foundations of our present knowledge by the 
method of experiment, the habit of questioning nature, instruments in 
hand, had as yet by no means become general. This habit of direct 
experimental research is certainly in large degree to be credited to the 
present century. Without stopping to enumerate the leading achieve- 
ments of physics during the century, let us take as illustrations a few 
leading cases. Nothing has, perhaps, done more to change the face of 
the earth, from the point of view of man, than the invention of the steam- 
engine and of the railway thereby made possible, of the telegraph and 
telephone, while the transmission of energy by electricity bids fair to 
rival them in importance. Let us then briefly consider what led to these 



Physics. 87 

inventions. At the beginning of the century it was universally held that 
heat was a substance, which could be put into, or removed from, ordinary 
matter. It is to the experiments of one of our own countrymen, the 
celebrated Count Rumford, that was due the original assault on this 
notion, the last blow at which was delivered by the Englishman, James 
Prescott Joule, in his great discovery of the mutual convertibility of heat 
and mechanical work, and of the doctrine of the Conservation of Energy. 
This discovery, so simple that it may be understood by every one, namely, 
that for whatever we do we get an exact equivalent, neither more nor 
less, is the fundamental truth of physical science. It is in physics the 
supreme achievement of the century. Until it was discovered, a true 
understanding of the principles of the steam-engine could not be arrived 
at, although the way had been prepared by the theoretical work of a 
French engineer, the illustrious Sadi Carnot. To Carnot and Joule, then, 
we owe the two laws of the new science of Thermodynamics, or the 
relations between heat and work, which lie at the basis of all steam, 
gas, oil, or other heat engines, as well as of all freezing machines, and 
of transmission or storage of energy by means of compressed gases. 
It would be well, therefore, for all intending investors in new and 
promising compressed or liquid air companies, no matter how attrac- 
tively advertised, to find out what thermodynamics has to say of the 
propositions advanced. 

The foundations having been laid by the experimental work of Joule 
and the theoretical work of Carnot, the required knowledge of the prop- 
erties of steam and other vapors used in engines and cooling machines 
was furnished by a masterly series of experimental researches of the dis- 
tinguished French physicist, Henri Regnault, who was set at work by 
the French government, and whose work has ever since been classical. 
No engineer could to-day design an engine without making use of the 
data thus furnished. 

Let us pass on to the telegraph. Here again it was the patient work 
of our countrjrman Henry, working quietly with purely scientific aims in 
his little laboratory in Albany, — it was Henry's investigations on the 
electromagnet that made feasible the invention by Morse of the recording 
telegraph, which is still in use more than any other system all over the 
world. It is, however, when we come to the great question of submarine 
telegraphy that we see most emphatically the practical contribution of 
pure science. The problem of telegraphing through an insulated wire 



88 Department of 

immersed in water is totally different from the corresponding one for a 
land line, and for years seemed hopeless of solution. The construction of 
a cable reaching from Europe to America was such a costly undertaking 
as to deter the most venturesome capitalists, unless they could be pre- 
viously furnished with a reasonable guarantee of success. It was here 
that the work of William Thomson, to-day known as Lord Kelvin, our 
greatest living physicist, furnished the necessary assurance. Taking up 
the purely mathematical problem of the propagation of an electrical 
impulse in a submarine cable, he for the first time set its mode of work- 
ing in a clear light, and by means of his solution predicted that the 
American cable, if constructed in accordance with his specifications, was 
bound to work. Led by faith in this statement, Cyrus W. Field col- 
lected the money, the cable was laid, and the cable worked. That the 
first cable of 1858 lasted but little more than a month was due to the 
unfortunate mode of working adopted by the chief electrician, a so-called 
practical man, who would however have been much better off if he had 
possessed the theoretical knowledge of Professor Thomson. To-day 
twelve working cables span the Atlantic, representing an investment of 
eighty-five million dollars. Is this too large a sum to credit to theoretical 
physics ? The problem of telegraphy that is to-day most interesting is 
that of telephoning across the Atlantic, and I feel no hesitation in saying 
that before this can be accomplished a large amount of theoretical research 
will be necessary, together with such experimental work as may be car- 
ried on in laboratories like ours, and is now being carried on by Professor 
Pupin of Columbia University, before a single dollar is sunk under the 
sea. 

The question of electric power transmission is one whose genesis is 
easy for all to remember. All do not remember, however, that far from 
electrical science being, as the newspapers maintain, in its infancy, the 
laws governing our dynamos and motors were discovered in the first quar- 
ter of the century, mainly by two princes among workers in physics, the 
Frenchman Ampere and the Englishman Faraday. The achievement of 
Ampere in discovering the laws of the action of electrical currents in 
producing magnetic forces upon each other was, in its combination of 
mathematical and experimental brilliancy, one of the most remarkable 
achievements in the annals of science. Still more important practically 
were the discoveries of Faraday, who deduced unaided all the laws upon 
which the working of dynamo-machines depends. 



Physics. 89 

Another illustration of our point is the wireless telegraphy of Mar- 
coni, of which we hear so much in the newspapers to-day. What the 
newspapers do not tell us is that the electrical waves made use of in tele- 
graphing across the English Channel were predicted in a paper published 
in 1864 by the great English physicist, Clerk- Maxwell, who completely 
remodelled the theory of electricity as it then existed. Twenty-three 
years afterward his predictions were experimentally verified by Hein- 
rich Hertz, who thus rendered the practical results of Marconi possible. 

These researches, far-reaching as were their practical results, were 
carried on by purely scientific workers, solely for the interest that they 
presented by increasing our knowledge. This should always be the posi- 
tion of the scientist, for, if he turns aside, attracted by the seductive 
paths of moueymaking, he is almost sure to lose the prize of the great 
discovery. 

Let us now turn to the present means of advancing our scientific 
knowledge. It is not to be overlooked that many of the great discoveries 
above mentioned were made with very simple apparatus and with very 
modest facilities. When we see the very primitive instruments of 
Ampere, Henry, and Faraday, we are led to wonder that they could pro- 
duce such accurate results. The days of such work are however over. 
It is now possible to add to the knowledge already so richly harvested 
only by experiments of the most careful nature and by measurements of 
great refinement, involving often complicated and expensive apparatus. 
It is for this reason that the great laboratories have sprung up, which we 
find in such large numbers both in this country and in Europe. Until 
about a quarter of a century ago there were none. It had, however, come 
to be recognized that, in order to make an investigator of a student, it was 
necessary not only that he should hear lectures, but that he should him- 
self have practice in experimentation and in the making of exact meas- 
urements. For these purposes, courses of instruction in physical measure- 
ments were planned, and laboratories where they might be practically 
carried on were erected. One of the earliest of these teaching labora- 
tories was that of the Massachusetts Institute of Technology, presided over 
by Professor Pickering, now director of the Harvard College Observatory. 
Later came the laboratories at Yale, Harvard, Cornell, Johns Hopkins, 
Chicago, and Columbia, costing between one and two hundred thousand 
dollars each. In each case is to be added the sum of from twenty to 
fifty thousand dollars for equipment with apparatus. During the same 



90 Department of 

time a large number of physical laboratories have been built in Europe, 
some of them involving a still larger expenditure of money, notably the 
one at Ziirich, in which the Swiss government invested about a quarter 
of a million of dollars. At all these laboratories both teaching and the 
performance of research were contemplated, and an idea of the results 
achieved may be obtained from the statement that from the Johns Hop- 
kins laboratory have issued upwards of five hundred papers, and from those 
of Harvard and Cornell in the neighborhood of one hundred each. 

Besides these institutions so immediately connected with teaching, 
another type of laboratory has made its appearance within the last ten 
years. Of this the most conspicuous example is the German Imperial 
Physico-technical Institute, which is separated from teaching, and is 
intended solely for the performance of research, especially for the per- 
formance of such measurements as would require resources exceeding 
those possessed by private or university laboratories. The work per- 
formed in this great institution has been of the highest class, and has 
drawn the attention of other governments to the desirability of establish- 
ing such national laboratories, with the result that England has now fol- 
lowed the example of Germany, though upon a smaller scale. A further 
example is presented in the Faraday-Davy research laboratory in London, 
the gift of a private individual, Mr. Ludwig Mond, a successful technical 
chemist, who in this most appropriate manner recognized the debt of 
applied to pure science by the foundation of a laboratory devoted espe- 
cially to the furtherance of research in physical chemistry. 

What, then, has been the position occupied by Clark University in 
the ranks of this march of progress ? Naturally it has been a modest one. 
Without a separate laboratory building, with a small equipment, and a 
staff reduced to the minimum, it has of course not been able to rival in 
quantity the work of its greater predecessors. It may, however, be re- 
marked that limitations of size are not necessarily limitations of quality. 
The relatively small number of students coming here have received greater 
individual attention than would have been possible at more crowded 
institutions. In spite of our limited space and equipment, it has always 
been found possible to put in possession of each student apparatus suitable 
for the performance of original research, and to give him what is more 
important, minute personal direction and encouragement. In this manner 
students coming to us from the colleges, often ill prepared for the severe 
mathematical work so necessary to the physicist, but to which they have 



Physics. 91 

been little accustomed, are rapidly pushed on, and recover their places in 
line. 

The Department of Physics was, during the first three years of the 
history of the University, under the direction of the distinguished physi- 
cist, Professor Albert A. Michelson, who was then called from it to take 
the conduct of the larger department at the University of Chicago. 
During his stay at Clark Professor Michelson was engaged in research 
in the field of optics, inventing a method for the study of radiations from 
both celestial and terrestrial bodies, by means of an instrument devised 
by him, and depending on the interference of light. By means of this 
ingenious and elegant method, valuable results in connection with spec- 
troscopy and the measurement of small astronomical objects were obtained, 
upon which a number of papers were published. Before the termination 
of his labors here, Professor Michelson was invited by the International 
Bureau of Weights and Measures to make, by means of his new apparatus, 
a comparison between the international standard of length and the length 
of a certain wave of light, thus establishing a natural unit of length. 
A new apparatus having been designed and constructed under the direc- 
tion of Mr. F. L. O. Wadsworth, preliminary observations were made at 
the University, and, obtaining leave of absence. Professor Michelson and 
Mr. Wadsworth proceeded to Paris, where the experiment was carried 
out with marked success, constituting a performance in metrology that 
win undoubtedly become classical. 

During his conduct of the department, Professor Michelson delivered 
usually one lecture a week, on various subjects concerning the Theory 
of Light, especially connected with his own researches. Upon the be- 
ginning of the incumbency of the writer, a consecutive course in theoreti- 
cal or mathematical physics was planned, and has been regularly delivered, 
the course covering five lectures a week for a term of two years. Per- 
haps the principal claim that can be made for the department is the stress 
that has been laid upon the subject of mathematical physics, undoubtedly 
the most difficult branch for the student, and one which has not yet be- 
come popular in this country, yet which is of prime importance, and 
without which none can hope to reach the highest position in the science. 
A gratifying testimonial to the truth of this contention is furnished by 
the recent arrival at the University of two students, both doctors of phi- 
losophy from German universities, who have come here impressed with 
their need for more study of mathematical physics. 



92 Department of 

In this course the several parts of the subject are treated in regular 
order, as parts of a logically connected whole, starting from the funda- 
mental basis of dynamics. The course is attended by every student in 
the department, and he is held responsible for a knowledge of its subject- 
matter in his examination for the doctor's degree. It is safe to say that 
in this respect the requirement for the degree is not exceeded at any 
institution in the country. The regular courses of the cycle are as 
follows : — 

1. Dynamics. — General Methods, Canonical Equations, Methods of Hamil- 
ton and Jacobi, Systems of Particles, Eigid Bodies. 

2. Newtonian and Logarithmic Potential Functions, Attraction of Ellipsoids. 

3. Elasticity, Hydrodynamics, Wave and Vortex Motion, Dynamical Basis 
of Sound and Light. 

4. Electricity and Magnetism. 

5. Optics, Physical and Geometrical. — Elastic and Electromagnetic Wave- 
theories. 

6. Thermodynamics, Thermo- and Electro-Chemistry, Kinetic Theory of 
Gases. 

7. The Partial Differential Equations of Mathematical Physics. 
Laplace's Equation, Equation of Thermal and Electrical Conduction, 

Equation of Wave-motion, Telegrapher's Equation, Developments in 
Series, Legendre's, Laplace's, Bessel's, and Lame's Functions. 

Besides these, it has been the practice to deliver each year at least one 
new course, so that certain courses are delivered occasionally. A num- 
ber of courses in pure mathematics have also been delivered at various 
times, supplementing those of the mathematical department. These 
extra courses have been as follows : — 

Dynamics of Cyclic and Oscillatory Systems, with applications to the The- 
ory of Electricity, Sound, and Light. 

Comparison of the Theories of the Ether. 

Theory of Functions of Real and Complex Variables. 

Definite Integrals, Fourier's Series. 

Ordinary Differential Equations. 

Linear Differential Equations, particularly of the second order. 

Elliptic Functions (notation of Weierstrass), with certain physical applica- 
tions, including the theory of the Top. 

Orthogonal Surfaces and Curvilinear Coordinates, and their applications. 

Of the lectures in the above course one volume, on the theory of elec- 
tricity and magnetism, has been published, and has apparently been of use 



Physics. 93 

to teachers in other institutions. Other volumes are in course of prep- 
aration. 

In addition to the lectures, a weekly colloquium or meeting for the 
discussion of questions in experimental physics has been held. Here 
reports upon current articles in the leading physical journals are deliv- 
ered by the students, and the most important classical determinations are 
also taken up, in order that familiarity may be gained with the methods 
of the masters of research. These meetings have been of great help to 
students, and have given them practice in presenting their ideas before 
an auditory. Beside the work of instruction, research has been carried 
on in the laboratory by every student and the professor. When a stu- 
dent arrives at the University he is at first put at work upon a subject 
designed to test his powers, and to give him familiarity with the princi- 
ples of exact measurement. When he has shown his ability, he is encour- 
aged to undertake a research for himself, under the continual guidance 
of the professor. In this way the undertaking of research before the 
necessary experience has been gained is prevented, and the publication of 
trifling or ill-considered articles is discouraged. As a rule a student 
devotes at least two years to the preparation of a doctor's dissertation. 
Thus the number of published researches is limited. Six doctor's disser- 
tations have been published, and another is ready for publication. Be- 
side these a number of other researches, both theoretical and experimental, 
have been published, one of which latter was honored by a substantial 
money prize in an international competition. These researches have not 
been confined to any one branch of physics, but have dealt with molecular 
physics, electricity, magnetism, and sound. Most of them have been of 
such a nature that the student was forced, not to work in a single narrow 
specialized line, but to gain a large amount of experience in various parts 
of the subject. A research of this nature is of far more value to the 
student than one performed simply for the purpose of gaining him a de- 
gree, and dealing only with a narrow range of ideas. 

The subjects of the dissertations have been as follows : Mr. T. P. Hall 
worked out a new method for the determination of the surface tension 
of liquids, suggested by Professor Michelson, in which the pull upon a 
film of liquid was directly weighed by a balance. Mr. C. A. Saunders 
made a determination of the velocity of electric waves in parallel wires, 
by a direct method, in which the wave-length and period of the waves 
were measured, the latter by photographing the periodic spark giving 



94 Department of 

rise to the wave by means of a revolving Foucault mirror, the wave- 
length by measuring the length of the wires, which was made to be a 
quarter wave-length by means of electrical resonance. This research 
demanded a large amount of time, and elaborate apparatus. In connec- 
tion with the revolving mirror a convenient method devised by the writer 
for maintaining a constant angular velocity was made use of. Mr. T. W. 
Edmondson determined the distances necessary for the formation of a 
spark at varying potentials between spheres of different sizes in air and 
in various insulating liquids, the potentials being measured by means of 
an absolute attracted disk electrometer. Mr. S. N. Taylor made a com- 
parison between the important cadmium element devised by Weston with 
the well-known Latimer Clark standard cell, in which he compared their 
electromotive forces by means of an electro-dynamometer, obtaining 
results agreeing remarkably well with those obtained by a quite different 
method at the German Reichsanstalt. Mr. W. P. Boynton carried out 
an experimental verification of the theory of the action of the peculiar 
high-frequency induction coil invented by Elihu Thomson and Tesla, 
which had never been mathematically treated in detail, not to say experi- 
mented upon. This work involved a large number of diificult measure- 
ments, including the currents, potentials, and frequencies of oscillation 
involved in the working of the apparatus. The results were in excellent 
agreement with the theory, considering the difficulty of the experiments. 
Mr. A. P. Wills undertook the development of a new and ingenious 
method, suggested by the writer, but materially improved by him, for 
measuring the magnetic permeability of substances, whether magnetic 
or diamagnetic, differing so little in this respect from air as to be not 
amenable to the usual methods. By means of a simple arrangement 
involving the use of a slab of the substance suspended in the field of a 
powerful electromagnet with peculiarly shaped pole-pieces, the effect was 
measured by the pull on a sensitive balance, so that accurate results were 
easily obtained. This work of Mr. Wills resulted in his being received 
into the laboratory of Professor du Bois, one of the leading authorities in 
magnetism, in Berlin, where he performed a number of other interesting 
pieces of research in the same subject. Mr. B. F. Sharpe spent the 
greater part of three years in developing a method devised by the writer 
for the measurement of the intensity of sound, a measurement of more 
than ordinary difficulty. The instrument depends upon the application 
of Michelson's interference methods to the measurement of the very small 



Physics. 95 

distances involved in the vibration of plates set in motion by sound. 
The interference bands observed in an interferometer, of which one mova- 
ble mirror is fixed upon a plate of thin glass forming the back of a reso- 
nator, are observed through a moving telescope, or have their motion 
photographically registered. In this manner a very sensitive means of 
measurement is obtained, and it is possible to measure sound in absolute 
measure, even when it is rapidly varying in intensity, a result not before 
attainable. The applications of this method which have been already 
suggested are very numerous and important. 

Mention should not be omitted of the labors of Mr. F. L. O. Wads- 
worth, who, as assistant to Professor Michelson, by his untiring energy 
and especial skill in the design and construction of apparatus, contributed 
in large measure to the success of the researches of the latter. 

The most important experimental paper published by the writer was 
a determination of the period of electrical oscillations in a circuit contain- 
ing a condenser and a coil, the purpose of the investigation being to 
verify the formula of Lord Kelvin, aU the constants of the apparatus 
being measured in absolute measure. For the research a new instru- 
ment was devised capable of breaking two electrical contacts at instants 
separated by a very small measured interval of time. The instrument 
was very sensitive, permitting the appreciation of less than a millionth of 
a second. This research, already begun in the attempt to improve a 
method for the determination of the ratio of the two units of electricity, 
was found to correspond to a question proposed by a committee in Paris 
having in charge the prize established by Elihu Thomson, and being sub- 
mitted for the competition, was awarded the prize of five thousand 
francs. 

During the first year of the history of the University a considerable 
sum was spent upon a set of meteorological instruments, especially for 
the study of atmospheric electricity, and research was begun in this 
subject by Mr. Alexander McAdie, of the Weather Bureau, who has now 
become a recognized authority upon the subject of lightning discharges. 
This work came to an end upon the departure of Mr. McAdie from the 
University, but it might with advantage be resumed, with the addition of 
observations of phenomena of terrestrial magnetism. 

In concluding this report, it will not be out of place to speak of the 
needs and ideals of the department for the future. It is extremely 
desirable that the courses in mathematical physics be repeated every year. 



96 Department of 

instead of once in two years as at present, this being as often as the time 
and strength of a single lecturer will allow him to cover the subject. If 
this were done, students could then begin each year at the most appropri- 
ate part of the course, without waiting for the natural beginning in their 
second year, as is now necessary for those students coming in alternate 
years. Even more desirable than aid in instruction is assistance in 
experimental work. Research in the laboratory can be carried out much 
more economically if a number of assistants are available to carry out 
details, leaving the professor free for the more important work of 
planning and personally attending to the more difficult parts of the 
work. 

One of the most important adjuncts of the department, the workshop, 
in which a skilled mechanic is constantly employed in the construction of 
apparatus for research, is capable of great extension of facilities. The 
absolute necessity of this work cannot be too strongly emphasized, and 
the department could even at the present moment profitably employ two 
or three men instead of one. Research in physics demands instruments 
of great exactness, complication, and cost, so that the maintenance of 
such a department in which research is done entails more expense than 
that of any other scientific department, except engineering. Each partic- 
ular research requires much of the apparatus used in it to be particularly 
designed, so that in view of the frequent changes necessitated before 
it exactly fits its purpose, and of the fact that it is impossible as a rule to 
find it kept in stock by dealers, it is more economical to have apparatus 
constructed in the workshop of the department under the eye of the 
professor than to have it made elsewhere. 

In designing an ideal laboratory, one of the first things to be con- 
sidered would accordingly be a workshop well equipped with modern 
machine tools, with an ample and convenient source of power for driving 
them, and with a large electric storage plant, both as a source of supply 
for investigations in electricity and magnetism, and for the purpose 
of furnishing power in smaller quantities than would require the main 
supply. An optical shop would greatly increase the capability of a 
laboratory for work in light. That such a suggestion is not extrava- 
gant is shown by the fact that Professor Michelson's new and ingenious 
echelon spectroscope was constructed by methods devised by him in the 
workshop of his laboratory, and could not have been so well constructed 
anywhere else. The famous diffraction gratings of Professor Rowland 



Physics. 97 

have for years furnished a further striking example, forcing European 
physicists to send to this country for their supply. 

A laboratory should be provided with the means for the determina- 
tion of the important physical constants of nature, such as the velocity 
of light and of electric waves, of the Newtonian constant of gravitation, 
of the mechanical equivalent of heat, and of the fundamental relation 
between electricity and magnetism, the so-called " v " of Maxwell. 
Thus it would be possible not only to initiate students into the most 
precise methods, but even to hope to improve upon classical determina- 
tions. Ample facilities should be always at hand for the comparison 
and calibration of the important physical standards of measurement, such 
as those of length, time, mass, of electrical and magnetic quantities. 
The small facilities in this line possessed even by our national govern- 
ment are in painful contrast to what is seen in Europe, particularly in 
the German Imperial Physico-technical Institute, in which a million or 
more of dollars is invested. 

Beside the matter of accurate measurements of well-known phe- 
nomena lies the wider field of research in fields which are sure to prove 
fertile in new discoveries. The great domain of electrical waves, a 
creation of the last decade, although already exploited by scores of 
observers, is still full of interesting problems, that are sure to yield a 
rich reward to those who shall devise more perfect methods of investiga- 
tion. The field of spectroscopy, whether in its terrestrial or celestial 
applications, is an enormous one. To this is to be added the study of 
radiations in general, of whatever character. The recent discovery of 
Rontgen was followed quickly by hundreds of researches bearing on the 
rays discovered by him, resulting in the discovery of several closely 
allied forms of radiation, and in a greatly increased interest in the 
phenomena of electrical discharges in vacuum tubes. Here remain a 
multitude of questions to be decided. The nature of cathode and of 
Rontgen rays remains to be settled, and will probably be one of the 
achievements of the early years of the next century. Research on the 
liquefaction of gases, and on the properties of bodies at temperatures 
not far removed from the absolute zero, until recently limited to a few 
observers possessing far more than ordinary facilities, will soon furnish 
a field for the labors of many, who will undoubtedly be well repaid. 
The many relations predicted by the recent applications of thermody- 
namics, especially in the domain of physical chemistry, remain in large 



98 Department of Physics. 

measure to be verified. The science of meteorology, hitherto largely 
an empirical one, remains to be put upon a satisfactory theoretical basis, 
and presents many problems for the physicist to attack in his laboratory. 
The same may be said of geology, which is, for example, vitally con- 
cerned with the thermal properties of rocks and other materials of the 
substance of the earth, and with many problems concerning the physics 
of the earth's crust. 

The foregoing is but a brief sketch of the field of physical investiga- 
tion. The enthusiasm of one devoted to the performance of research, 
and considering it the most attractive form of human endeavor, would 
enable him to enlarge the subject over many more pages than are here 
available. The field is enormous, and each new discovery leads to new 
paths of inquiry. It is obvious that, in order to enter upon these 
attractive fields of work, one must be provided with large resources. 
Is it unreasonable to look forward eagerly to the day when Clark 
University shall possess a well-equipped physical laboratory building, 
fitted out with the utmost that our knowledge can suggest, in which 
we may hope to contribute our just share toward the enlargement of 
the boundaries of science, and thus to the welfare of humanity ? 



DEPARTMENT OF BIOLOGY. 

By Clifton F. Hodge. 

PAST AND PRESENT STAFF. 

Charles 0. Whitman, Ph.D., Professor of Animal Morphology, 1889-92. 

Peanklin p. Mall, M.D., Adjunct Professor of Anatomy, 1889-92. 

Henet H. Donaldson, Ph.D., Assistant Professor of Neurology, 1889-92. 

Waeeen p. Lombaed, M.D., Assistant Professor of Physiology, 1889-92. 

Clifton F. Hodge, Ph.D., Assistant and Pellow in Neurology, 1889-91; 
Assistant Professor of Physiology and Neurology, 1892-. 

J. P. McMuEEicH, Ph.D., Docent in Morphology, 1889-91; Assistant Pro- 
fessor of Morphology, 1891-92. 

Adolf Meyee, M.D., Docent in Psychiatry, 1895-. 

tGEOEGE Baxje, Ph.D., Docent in Comparative Osteology and Paleontology, 
1890-92. Died June 25, 1898. 

John C. Caedwell, M.D., Assistant in Physiology, 1889-91. 

Sho Watase, Ph.D., Lecturer and Assistant in Morphology, 1890-92. 

FELLOWS AND SCHOLARS. 

Peanklin W. Baeeows, M.D., Pellow in Physiology, 1893-94. 

Chaeles L. Bristol, Fellow in Morphology, 1891-92. 

Heemon C. Bumpus, Pellow in Biology, 1889-90. 

Albeet C. Eycleshymer, Fellow in Morphology, 1891-92. 

Chaeles L. Edwards, Ph.D., Fellow in Morphology, 1890-92. 

R. R. GuELEY, M.D., Fellow in Biology, 1895-96. 

Homer Gage, M.D., Honorary Scholar in Anatomy, 1889-90. 

Edwin 0. Jordan, Fellow in Morphology, 1890-92. 

Heebeet p. Johnson, Fellow in Morphology, 1891-92. 

F. C. Kjenyon, Ph.D., Fellow in Biology, 1895-96. 

tW. E. LocKwooD, M.D., Fellow in Physiology, 1891-92. Died June 23, 1897. 

Feank E. Lillie, Fellow in Morphology, 1891-92. 

A. D. Mead, Fellow in Morphology, 1891-92. 

William S. Millee, M.D., Honorary Scholar, 1889-90; Scholar in Anatomy, 

1890-91 ; Fellow in Anatomy, 1891-92. 
James E. Slonakee, Fellow in Biology, 1893-96. 



100 Department of 

Colin C. Stewart, Scholar in Physiology, 1894-95; Fellow in Physiology, 

1895-97. 
Fkedeeick Tuckeeman, M.D., Ph.D., Fellow in Anatomy, 1889-90. 
William M. Wheelee, Fellow in Morphology, 1890-91 ; Assistant, 1891-92. 

SPECIAL STUDENTS. 

James Jenkins, Special Student in Biology, 1894-95. 
Preston Smith, Special Student in Physiology, 1899. 
W. G. Watts, Laboratory Steward and Special Student, 1889-91. 



HISTORICAL REVIEW. 



It will be seen from the above list of appointments that the depart- 
ment was organized to cover animal biology. Animal morphology, ver- 
tebrate anatomy, physiology, comparative osteology and paleontology, and 
neurology, which forms the natural transition to psychology, and has 
been classed in that department, formed a compact and well-selected 
group with which to begin work. This organization was still further 
strengthened by a strong force of organic chemists in this fundamental 
department. 

A good share of the equipment necessary for different lines of research 
work already in progress or planned by the different appointees had been 
ordered during the previous summer, so that the work of the whole 
department began practically with the opening of the University. Zeiss 
microscopes of the most approved patterns and with full complements of 
apochromatic eye-pieces and objectives, Thoma microtomes, together with 
those of Minot, the Minot-Zimmerman, Schanze, and others, complete assort- 
ments of chemical reagents, stains and laboratory tools, apparatus and 
glassware, all were supplied with liberality. Abundant and suitable 
rooms were also placed at the department's disposal in the main univer- 
sity building. Two large rooms and a convenient dark room for photo- 
graphic purposes on the fourth floor were assigned to physiology and 
were devoted to laboratory and lecture-room with workshop equipped with 
lathe and tools for working both wood and metals. Four large rooms on the 
third floor were arranged to accommodate anatomy and morphology for 
laboratories, lecture-room and drafting room ; and, in addition, four small 
rooms adjoining supplied office and library for the head of the depart- 



Biology. 101 

ment, and private laboratories for three of the docents and assistants. 
Two rooms on the second floor, adjoining the psychological department, 
were assigned to neurology, the one for private laboratory and office of 
Assistant Professor Donaldson, the other for his general laboratory. All 
of these rooms were equipped with water and gas, and some with hoods to 
render them the most convenient and ideal laboratories possible, and the 
morphological laboratories were furnished with five large aquaria, the 
largest being eight feet in length, all supplied with running water, and a 
large number of smaller glass aquaria which made it possible to keep all 
sorts of aquatic animals both summer and winter. 

While the chief emphasis both as to equipment and disposition of the 
instructor's time was given to research, the side of instruction toward 
breadth and depth of view, so necessary to the highest type of investiga- 
tion, was not neglected. Models of the brain (Auzoux, Aeby, Ziegler), 
as well as Ziegler 's models of classic embryological types, and a complete 
set of Leuckart & Nitche's zoological charts, and an extensive library 
of wall charts copied from various monographs and text-books, all 
these, supplemented by anatomical and zoological specimens, gathered 
as rapidly as possible to form the nucleus of a museum, imparted the 
best possible quality to the work of instruction. In fact, instruction 
and research began together and went hand in hand, the one aiding the 
other. 

Professor Whitman immediately began courses of lectures funda- 
mental to the doctrine of evolution. The first of these treated, 
entirely from original sources, the historical development of Compara- 
tive Anatomy, beginning with its renaissance in the works of Marco 
Aurelio Severino (" Zootomia Democrit^a, id est Anatome generalis totius 
animalium opificii libris quinque distincta," 1645), and bringing the sub- 
ject down to the discussions, just preceding the Darwinian epoch, 
between Etienne Geoff roy Saint Hilaire and Georges Cuvier (1830). 
As Professor Whitman himself announced with reference to this early 
course : " Attention will be directed particularly to the origin and 
development of historic ideas, tendencies, methods, and schools, as pre- 
sented in the early iatric and physiological stages of Zootomy ; in the 
works of Haller, Geoffrey, and Cuvier ; in the ' Anatomic Philosophique ' 
of the French, and the ' Naturphilosophie ' of the Germans ; in the 
doctrines of the ' Scale of Nature,' ' Unity of Composition,' and of 
' Types ' ; in the hypotheses of Evolution and Epigenesis, in Homology 



102 Department of 

and Teleology, etc. The biographical side of the subject "will also 
receive due consideration, especially in the cases of such representa- 
tive men as Malpighi, Swammerdam, and Leeuwenhoek of the seven- 
teenth century, and Haller, Buffon, Daubenton, Linn6, John Hunter, 
Camper, Vicq-d'Azyr, Kielmeyer, Geoffroy, and Cuvier of the later 
period." 

A second and third historical course was devoted respectively to the 
subjects of Generation and Comparative Embryology. These courses, 
compactly coordinated, and following logically on the development of 
comparative anatomy, were likewise worked up from original soiirces 
in Aristotle, Harvey, John Hunter, Wolff, Von Baer, and others, and 
led naturally up to the modern doctrines of heredity as developed by 
Lamarck, Darwin, Weismann, and their followers. Especially in the 
course in Comparative Embryology, the present phase of biological work, 
cytological technique and terminology, were fully treated, together with 
matters of interest in recent discussions as to origin and maturation 
of ova and spermatozoa, phenomena of fecundation, cleavage of the 
ovum, with comparison of different types of cleavage and experimental 
researches in cleavage, gastrular and pre-gastrular stages, their differ- 
ent types and derivations, germ layers, the trochosphere, budding and 
fission, formation of the embryo in invertebrates and vertebrates, to- 
gether with that of double and multiple monsters, and, finally, the 
course culminated in a discussion of the origin and significance of 
metameric segmentation. 

Simultaneously with these courses Dr. McMurrich lectured on the 
coelenterates and platyhelminths, sifting all discoverable evidences for 
ccelenterate ancestry of the worms, the origin of segmentation, and 
the significance of coelenterate structure in gastrular stages of vertebrate 
embryos. Dr. Baur on the side of paleontology discussed the osteology 
of reptiles and mammals, living and extinct. Dr. Bumpus also lectured 
on the affinities of the Crustacea. 

For two years, as a means of uniting still further instruction and 
research, and of keeping all members of the department in touch with 
one another, an active biological club was maintained. Monthly meet- 
ings were held, and at each a carefully prepared lecture was read and 
discussed. The subjects of these lectures indicate to such an extent 
the lines of interest developed in the department, that a list for 1890- 
92 is given in full. 



Biology. 103 

1. Scope and Aims of the Club. — C. 0. Whitman. 

2. Ideas on the Origin of the Galapagos Islands and the Origin of Species. 

— Geo. Baur. 

3. Insect Metamorphosis. — W. M. Wheeler. 

4. The Origin and Significance of the Blastopore. — J. P. McMurrich. 
6. Nitrification and Nitrifying Organisms. — E. 0. Jordan. 

6. The Animal Ovum. — Sho Watase. 

1. The Salisbury Expedition to the Galapagos Islands. — Geo. Baur. 

2. The Third Eye of Vertebrates. — A. C. Eycleshymer. 

3. Some Points in the History of Bacteriology. — E. 0. Jordan. 

4. Amphimixia in the Protozoa. — H. P. Johnson. 

5. Nervous System of Mollusca. — F. E. Lillie. 

6. Germ Cells. — Sho Watase. 

7. Mammalian Spermatogenesis. — Sho Watase. 

8. Metamerism in Arthropods. — W. M. Wheeler. 

The scope of work of the morphological section will be seen more 
fully in the list of investigations which follows, under the heading of 
Research Work, which has been grouped together for aU divisions of the 
biological department. 

In Vertebrate Anatomy, Dr. Mall lectured for three successive years 
on the histology of tissues arising from the mesoderm, on the develop- 
ment of serous and blood spaces in vertebrates, and on the development, 
histology, and comparative anatomy of the organs arising from the 
endoderm. Dr. Tuckerman lectured in connection with his research 
work, on the gustatory organs of mammals, and Dr. Miller likewise on 
the lobule of the lung with its blood-vessels. 

In Physiology Dr. Lombard devoted a series of lectures of a year 
each, supplemented by numerous demonstrations, to the following sub- 
jects : — 

1. Physiology of Muscle and Nerve. 

2. Physiology of Circulation and Eespiration and the Nervous Mechanisms 
by which they are regulated. 

3. Physiology of Muscle, Nerve, and Spinal Cord. 

Dr. Cardwell gave a number of lectures upon Animal Locomotion 
and Coordination. And Drs. Hodge and Jordan lectured respectively 
on the Physiology of Spinal and Peripheral Ganglia, and the Physiology 
of Leucocytes. 



104 Department of 

A convenient laboratory was fitted up with microscopes, microtomes, 
and all needed instruments, materials, and reagents for neurology. A 
number of brain and other neurological specimens were prepared for 
purposes of instruction and demonstration, and the best neurological 
models were purchased with this end in view. 

Dr. Donaldson lectured during 1889-90 on the anatomy of the central 
nervous system in man ; and in 1890-91 completed the course by treat- 
ing the peripheral nervous system and discussing at length the various 
physical measures, so-called, of intelligence as found in the brain, its size, 
weight, convolution, thickness of cortex, and relative development of 
lobes, as these have been presented in the history of neurology. The 
course was repeated in 1891-92, together with a practice course in the 
laboratory on the histology of the nervous system. 

A seminary which met once a week was devoted to the reading of 
papers on neurological topics, both of historical and current interest, and 
to reports on work in progress in the laboratory. 

The primary aim of the department, as Professor Whitman expressed 
it, is to make " research men," men imbued with the spirit and desire for 
original investigation. This purpose is seen in all the courses of instruc- 
tion and becomes even more patent in the number of investigations actually 
in progress in the different laboratories of the department. In fact, the 
serious work of every member was research, for which lecture and semi- 
nary combined to form an appropriate historical and philosophical back- 
ground. 

During this period, Professor Whitman being in charge of Woods 
HoU Marine Laboratory, practically all the men in morphology continued 
their studies there through the summer seasons, taking microscopes, 
apparatus, and reagents from the University. Lectures were also given at 
Woods Holl by Professors Donaldson, Lombard, and McMurrich, and 
Drs. Watase, Wheeler, and Jordan assisted Professor Whitman with 
the laboratory instruction. 

The following resume is given to present a general picture of the 
spirit and scope of the department's work during this three-year period. 

RESEARCH WORK. 

Professor Whitman, in addition to editing the Journal of Morphology, 
equipping and directing a new and complicated laboratory, and giving 



Biology. 105 

regular lectures, spent most of his time investigating the Hirudinea, 
publishing a series of papers on their classification, with descriptions of 
new species, on their metamerism, and on their hypodermic impregnation 
by means of spermatophores. " Specialization and Organization," " The 
Naturalist's Occupation," and other papers show that he was following lines 
of more general interest both in scientific work and in public education. 

Dr. Baur was delving in problems of fundamental importance in com- 
parative osteology of vertebrates, morphology of the vertebrate skull, 
carpus, ribs, etc., and working out the descriptions of a number of forms 
discovered during his successful paleontological expeditions. A good 
share of his work grouped itself about the plan of his great expedition to 
the Galapagos Islands, which was finally made possible by the munificence 
of the Hon. Stephen Salisbury, together with contributions from Pro- 
fessor H. F. Osbourn and from the Elizabeth Thompson Science Fund. 
This trip Dr. Baur made (in company with Mr. C. F. Adams) be- 
tween May and October of 1890, visiting all the islands, excepting Nar- 
borough, Wenman, and Culypepper. Extensive collections of both flora 
and fauna were obtained, which were worked up by Dr. Baur himself and 
by specialists both in this country and in Europe. The main general 
result of the expedition was a demonstration of the fact that the life on 
these islands is harmonious, and hence that the islands themselves must be 
explained on the subsidence theory, rather than on that of emergence as 
held by Darwin, Wallace, and others. 

Dr. McMurrich devoted his time chiefly to investigating the morphol- 
ogy and embryology of the Actinozoa, and from these researches derived 
his conclusions as to the phylogeny of the group. Dr. Watase was at work 
on various fundamental problems on the cell, caryokinesis, cleavage of the 
ovum, spermatogenesis, and sex differentiation. 

The research work of other members of the depairtment was dis- 
tributed as follows : Mr. Johnson investigated the morphology and 
biology of the Stentor. Mr. Lillie studied the embryology of Unio. Dr. 
Wheeler worked upon the embryology of the Insecta, and in that connec- 
tion investigated the neuroblasts in the Arthropod embryo. Dr. Bumpus 
completed his study, already under way, upon the embryology of the 
American lobster. Dr. Edwards studied the embryology of the Holo- 
thurians. Dr. Jordan studied the life history and embryology of the 
common newt ; and Mr. Eycleshymer made a special investigation of the 
development of the optic vesicle in the amphibian embryo. 



106 Department of 

In the closely allied field of vertebrate anatomy, Dr. Mall was making 
a minute study of a human embryo, investigating the formation of the 
lesser peritoneal cavity in birds and mammals, the motor nerves of 
the portal vein, and also completed his important work on a new connec- 
tive tissue element, the reticulated connective tissue, with its distribu- 
tion in the body. Dr. Tuckerman carried on an extended research on 
the gustatory organs of a series of animals, and their development in man. 
Dr. Miller also worked out the minute anatomy of the lung, and by a most 
exhaustive and varied method succeeded in demonstrating for the first time 
the manner of ending of the terminal bronchi, together with their relations 
to the arteries, veins, and capillary system. On the side of practical surgery 
Dr. Homer Gage conducted a series of experiments on intestinal suture. 

In physiology Dr. Lombard continued his investigations on effect 
of fatigue on voluntary muscular contractions and alterations in strength 
which occur in severe muscular work, and on the conditions, barometric 
pressure, temperature, sleep, food, alcohol, and tobacco, which effect 
voluntary effort. Dr. Cardwell investigated the physiology of the 
cerebellum with relation to animal locomotion and coordination. 

For neurology Dr. Donaldson was pursuing a similar plan with that 
followed by Dr. Whitman in morphology, viz., gathering the history of 
the science from original sources, and reducing to uniform statements, 
tables, and curves all the data as to size and weight, both relative and 
absolute, of the brain. In this connection he made an exhaustive 
study, both gross and microscopical, of the brain of Laura Bridgman. 
An extended series of observations was also being carried on in the 
laboratory upon the influence of hardening reagents upon brain weight 
and specific gravity. Dr. Hodge worked for two years (1889-91) 
on the physiology of nerve cells, their diurnal fatigue and recovery in 
sleep, and their recovery from effects of electrical stimulation. Dr. 
Donaldson, with Dr. Bolton, completed a study of the size of the cranial 
nerves in man, and Dr. Bolton studied microscopically the spinal cord 
of a horse aifected with spring halt. 

The above gives, in the main, a picture of the work in progress 
during the first three years of the department's existence. All but 
one or two of the researches mentioned have been published, together 
with others not cited. For place of publication and the complete record 
the reader is referred to list of publications by members of the University 
for the corresponding years. 



Biology. 107 

If one science is entitled to claim the special interest of the founder 
more than another, biology is that science ; and in the organization of this 
department, the aim above all else was to make it the most ideal pos- 
sible place for biological research. Foundations were laid at this time 
for a special building more adequately to house this flourishing depart- 
ment. How well the ideal was realized may be seen from the estimate 
of Professor Whitman, whose experience in the laboratories of three 
continents entitles him to an opinion. Writing in 1899, he says, " The 
Clark University Ideal, as I understood it when connected with its early 
work, is the ideal which I place above any other thus far proposed, and 
I hope it may find strong friends to help it forward." Unencumbered 
by the burden of undergraduate courses, untrammelled by red tape and 
traditions, the laboratory formed for three brief years a veritable garden 
spot in the field of biological history in this country. It was a place 
where each man was free to devote all his best energies to just that 
which he wanted most to discover ; where the best thing a man could 
possibly do for himself constituted the highest service he could render 
to the University. 

A "Flying Squadron," has been suggested as the most fitting defi- 
nition for a university. Scarcely had this splendid organization been 
attained than it was carried off bodily, almost, to lay foundations for the 
biological department in a new university. While no higher tribute 
could have been paid to Clark University, it has left the department 
sadly crippled both for men and means for work. 

Since 1892 biology has been represented by but a single instructor, 
Dr. Hodge, who was recalled from the University of Wisconsin, with 
the title of Assistant Professor of Physiology and Neurology. For the 
first year Dr. Hodge offered only courses on the physiology, anatomy, 
and embryology of the nervous system. During the succeeding years, 
owing to the great need of having the subject presented, a course in gen- 
eral biology has been given, the aim of which is to present the funda- 
mental principles of the science. A sense of the importance of this 
course has grown from year to year, with the conviction that the sub- 
ject finds too little representation in most of our educational institutions ; 
and it is hoped, as soon as practicable, to develop it into a solid course, 
historical, philosophical, and practical, to extend through all of two and 
possibly three years of university study. The main courses offered by 
Dr. Hodge have related to anatomy and physiology of the nervous sys- 



108 Department of 

tern, both comparative and human, including the sense organs as well, 
and to the entire field of physiology and to that of embryology, especially 
of the nervous system and sense organs. These have been supplemented, 
wherever possible, by laboratory courses. A seminary meeting, usually 
one evening weekly, has been maintained, the plan of which has been, 
in the main, to spend a year upon each of the three following top- 
ics : 1, history of medicine, with special reference to physiology, epochs, 
schools, and men ; 2, history of, and present discussion centring about, the 
doctrine of evolution ; 3, development of neurology. A journal club, 
meeting weekly, has aided to bring all members of the department 
together for discussion of articles in current literature. In general, all 
seminaries and courses of instruction have been given with reference to 
furnishing aid and stimulus to students in their research work. 

In addition to the above, on the teaching side. Dr. Hodge has 
become interested in lines, especially of biological education in ele- 
mentary schools. A definite standpoint for elementary nature study has 
been developed, which is a distinct reaction against the tendency toward 
technicality, classification, and minutiae which have come to constitute so 
large a part of our elementary science courses. It is planned to include 
this in the general biology course by way of discussing the question. 
What aspects of biological science shall be taught in the elementary 
school ? The kind of physiology which should form a part of elementary 
education has also been given considerable attention. Both subjects have 
formed the basis for courses in the summer school. 

In passing to consider the research work of the department since Dr. 
Hodge took charge of it, a word as to its general purpose and plan will 
simplify the discussion. 

Science, in this country especially, has become unnecessarily arrogant. 
We hear on all sides such expressions as "pure science," a term which 
Huxley wished had never been invented, " truth for truth's sake " or 
" science for the sake of science," and the " uselessness " of science is 
made a boast. An important truth is stated in these expressions ; for 
science is of such paramount use and importance to mankind that to 
discuss this point with one who says it is not, is clearly " casting pearls 
before swine." Possibly another reason for resorting to these expres- 
sions is that the human values attaching to knowledge are so enor- 
mous that we have no measures or terms with which to adequately 
express them. However this may be, if science have a faith worthy 



Biology. 109 

of respect, it should result in mutual benefit to share it so far as pos- 
sible with a reasonable and intelligent public. 

A research laboratory is an institution the business of which is to 
investigate those problems which have either never been attempted or 
have hitherto baffled all efforts of the human mind to solve. These 
problems are not far to seek, but crowd upon our lives at every point. 
The values attaching to their solutions can be expressed only in terms of 
human life and happiness, compared with which the output of Klondikes 
and Cripple Creeks is but the small change of the hour. It is clearly 
recognized that we may not be able to estimate the value of truth until it 
be discovered, and that the investigator himself, who is willing to devote 
his time and energies to the work, should be the one to estimate its values, 
and that he should have the greatest freedom to select the task for which 
he knows himself to be best fitted. Still, one must be a man before he 
can be a scientist, and fundamental human values must be in the main 
the same for all. And it would seem to be the first duty of a research 
laboratory to devote its resources to the work of solving those problems 
which concern human life most closely, and possess the greatest human 
importance. A laboratory owes no less than this to a community ; or, 
better stated, a laboratory is that part or organ of a community differ- 
entiated to perform the special function of discovering and making avail- 
able whatever truth is of greatest value to its common life. 

In deciding the directions, therefore, which research work shall take, 
the above general policy has been followed, and it is a satisfaction to note 
that the same sentiment was prominently expressed at the founding of 
the University. On that occasion Mr. Hoar spoke as follows : — 

" Speaking now for myself alone, I have little sympathy with that arrogant 
and disdainful spirit with which some men who undertake, with little title, to 
represent science in this country, sneer at any attempt to make use of the 
forces she reveals to us for the service of mankind. Some one said the other 
day that science was becoming a 'hod-carrier.' I do not see why the term 
' hod-carrier ' should express the relation rather than the term ' benefactress.' 
I do not see, either, that there is anything degrading in the thought that 
the knowledge of the learned man enables him to lift the burden beneath which 
humanity is bowed and bent. I do not know that science is exempt from the 
divine law, ' He that is greatest among you, let him be the servant of all.' If 
the great forces of the universe perform all useful offices for man, if the sun- 
shine warm and light our dwellings, if gravitation move the world and keep it 
true to its hour, nay, if it keep the temple or cathedral in its place when the 



110 Department of 

hod-carrier has builded it, I do not see why it should not lend its beneficent aid 
to him also. Our illustrious philosopher advised his countryman to " hitch his 
wagon to a star." The star will move no less serenely on its sublime pathway 
when the wagon is hitched to it. I do not know that any archangel or god- 
dess, however resplendent the wings, has ever yet been constructed or imag- 
ined without feet. I do not know that any archangel, however glorious, has 
ever been created or imagined without sympathy for suffering humanity. 

" I look for great advantage to the country, both in wealth and power and 
in the comfort and moral improvement of the people, by the application of 
science to the useful arts." 

The manner in which tliis fundamental purpose has been carried out 
thus far may now be seen in part in the lines of work which have been 
carried out, and, more fully, in plans for the future. 

In this country of, so-called, nervous tension, nervousness and nervous 
prostration, nothing could be of greater value to the common life than 
knowledge of the fundamental laws of the working of nerve protoplasm. 
It is only in discovery and obedience to these laws that we may hope for 
escape from present evils and possession of sane and permanent national 
health. Consequently lines of investigation upon the physiology of 
the nerve cell have been kept open from the beginning. Continuing the 
studies mentioned in speaking of an earlier period in the history of the 
laboratory, the nerve cell has been studied during its electrical stimulation 
and also in connection with changes which occur in the process of aging 
and in death from old age. Dr. Barrows has investigated its appearance 
under various kinds of diet and when the body has been deprived of food, 
Dr. Stewart has studied the effect of alcohol on the cells of the cerebrum, 
cerebellum, and spinal cord. Drs. Starbuck and Lancaster respectively 
studied effects on the nerve cell of artificial (by means of electrical stimu- 
lation) and natural fatigue carried to an extreme degree. Dr. Kenyon 
devoted a year to a most successful study of the brain of the honey-bee. 
Dr. Burk devoted considerable time in working out the meduUation of 
the brain in puppies. Dr. Goddard tested by especially rapid methods 
of preparation theories as to the possible amoeboid movements of nerve 
cells in conditions of activity and sleep. Further experiments are now in 
progress on the influence of alcohol, and work has been begun on the 
effect of other chemical substances, notably strychnine, morphine, and 
nicotine on nerve cells. For the purpose of making possible a more prac- 
tical study of the human brain, a brain microtome has been devised in the 
laboratory by Dr. Goddard, with suggestions from Dr. Hodge. This 



Biology. Ill 

instrument is constructed on principles new to such microtomes thus far 
made, and has rendered it possible to cut sections of the entire human 
brain in any desired plane with the ease and uniformity with which smaller 
sections are cut by the ordinary microtomes. The blade of this microtome 
was made, and presented to the University, by the firm of Loring, Goes, & 
Co. of Worcester. 

A research less closely connected with the general plan, but still es- 
sentially upon the nervous system, was carried out by Dr. Slonaker upon 
the eyes of vertebrates. 

This line of work in the physiology of the nervous system is one 
which the department proposes to continue, as opportunities and properly 
prepared men present themselves, until, it is hoped, the American public 
may be able to live on more amicable terms with its "nerves." 

In order to attack, in a more fundamental manner, problems centring 
about the nerve cell and its normal activities, it has been necessary to 
make a wide detour of investigation in two directions. The first of these 
has consisted in a study of the microscopical appearances of lymph as 
compared with different special protoplasms under various methods of 
hardening and staining. This has proved to be a matter of fundamental 
importance to histology in general, and has demonstrated that, until we 
are able to gain some definite notion as to the substances in question, it is 
useless to go on figuring and describing " granulations," and " fibrillge," 
" alveoli," and the like. 

The other line of research to which study of the rhythms of the nerve 
cell has led logically is that of the physiological conditions in general 
which underlie and determine phases of animal activity. In other words, 
if we wish to learn the condition of nerve cells in states of rest and fa- 
tigue, we must study first the normal rhythms of activity and rest of our 
animal. Knowing tliis, we may be able to examine the nerve tissues at 
any desired point in the curve of functional activity. And in order to 
gain the fundamental laws of nervous activity, we need to study these 
rhythms of sleep and waking, rest and activity, which make up the normal 
flow of an animal's life, in a series of animals. This fundamental work 
has not been done for more than one or two forms as yet, and for those 
only in a preliminary way. Dr. Aikin's study of vorticella, which 
showed that a one-celled animal is capable of continuous activity so long 
as food and environment remain suitable, was the first on the subject. 
Stewart's experiments on the influence of barometric pressure and diet, 



112 Department of 

including alcohol, on the diurnal activity of rats and mice, together with 
Dr. Hodge's similar work on dogs and squirrels, serve further to indicate 
the possibilities in this field. These studies have pointed to the fact that 
the activity of each animal conforms to a type as to periods and rhythms 
which is characteristic of the species, and that the total amount of work 
developed is profoundly influenced by physiological conditions thus far 
investigated. These researches have been suspended for the present, 
but it is hoped to push the work in the near future along two main 
lines. The first of these aims to discover the typical rhythms of physio- 
logical activity for a series of animals, both invertebrate and verte- 
brate. It would seem that these physiological types are of even greater 
ultimate interest and philosophical importance than the purely structural 
and morphological types from which the comparative anatomists have 
worked out the evolutionary series. When this has been done, we shall 
be in position for the first time in the history of biological science to 
study human rhythms of activity and repose in the light of similar rhythms 
of the animal series, and to gain, possibly, some notion as to a norm for 
human work. The second line of study in this field essays to analyze the 
physiological conditions under which any particular animal is able to 
develop the greatest possible amount of normal activity. This is no less 
a problem at bottom than the study of the physiological conditions which 
underlie the highest possible types of human life and activity. 

The question naturally arises at this point as to what position the 
biological department of Clark University assumes upon some of the 
wider aspects of the science. 

Since the times when Aristotle employed the armies of Alexander the 
Great to collect specimens for his museums from all the then known 
world, the greater portion of biological effort has been directed toward 
classification and naming of animal and plant species. The uttermost 
corners of the earth have been searched to the tops of the mountains and 
dredged to the deepest ocean depths, all to discover some new species of 
animal or plant, while the common plants and animals of our dooryards 
are known scarcely more than in name. This classification work, ex- 
tending from Aristotle in Greece through Linne and Cuvier, Buffon 
and Brehm, to Agassiz in America, has been in part necessary and impor- 
tant. But, when it is possible to find single species which have been 
christened ten or even twenty times, it is safe to insist that the passion 
for naming things has been carried too far. This passion for names is 



Biology. 113 

characteristic of a certain period in infancy in the individual, and, we 
may hope, in the growth of a science as well ; and while it gives the best 
promise for the future, is it not time to hope that this phase of biology 
may wane, and the maturer work of learning the really important facts 
concerning animals and plants be seriously undertaken ? These facts of 
paramount importance have to do with the functions of species, the work 
species do in the world. As a matter of fact, to work in classification by 
methods of external characters the monumental work of Darwin and 
Wallace has long since put a final period. Species are not fixed immu- 
tably, but are plastic and normally variable. Embryological studies, 
even by Louis Agassiz himself, proved that animals repeat simpler stages 
of organization each in its own life history. With the doctrine of evolu- 
tion the whole method of the science has been changed. Deeper char- 
acters than those on the surface must be discovered, and only such as 
reveal blood relationships and indicate the true position of the species in 
the line of evolutionary descent can be of permanent importance in the 
new classification. Thus the past two decades have been devoted in 
biological laboratories largely to tracing most minutely the embryology 
of different species, and in exhaustive studies into comparative anatomy 
and embryology combined. There has been a constant gravitation, natu- 
rally enough, to again consider the findings of the microscope, arrange- 
ments of cells, and all the infinite variety of granule and rod and fibril as 
fixed entities, rather than again as plastic and possibly changing with 
every phase of functional activity. There has thus been no limit to the 
careful drawing and figuring and coloring of what are supposed to be 
important structures in living protoplasm. This may all be well enough 
as pastime. But where the idea of functional changes has been left out 
of account, the work is builded on the sand. It is like studying and map- 
ping the positions, forms, and colors of the clouds by means of the nice 
adjustments of the telescope. Many of the books of the past decade will 
be museum junk before 1910, if they are not already. We need to real- 
ize in our modern laboratories that turning the crank of a microtome in 
and of itself has no more educational value, possibly not so much, as 
turning the crank of a grindstone. In fact, our theories of laboratory 
research and even of laboratory instruction in the brief period in which 
these have come into prominence have gone far astray. In drifting 
away from all considerations of human good and even common sense, 
our modern laboratory work is in the same danger of becoming an end in 



114 Department of 

itself that sunk the old classification into a worse than imbecile waste of 
time. 

Furthermore, progress is the word which has characterized every 
expression of the purpose of the biological department. The advance- 
ment of science has been its fundamental raison d'etre from the beginning. 
There is little danger that the world will have too many institutions de- 
voted to the serious work of advancing science. The great difficulty has 
been, and, we may add, still is, that, after a period of great achievement, 
the inevitable tendency asserts itself to spin round and round about it as 
though there were nothing else ahead worth working for. The endless 
discussions of the past two decades reminds one of the hollow disputations 
of the scholastics. The coursing over and over again of the ground 
covered so well by Darwin and Wallace, and even by Aristotle, in great 
part, has been enough to raise the shades of some of these good men to 
urge us to cease hairsplitting and trifling, and go forward into the great 
field which their works have opened up. 

Their great contributions have consisted in demonstrating the plas- 
ticity of living forms, and the field which this presents is that of infinite 
possibilities of perfection and utilization in the future. It has opened up 
before us, instead of the dead finality, the idiotic circle with its endless 
round of " vanity of vanities," of the old philosophy, an infinite future 
of progress. In this progress Science must worthily lead, but may well 
hold Art by the hand, lest the doing of science, which is its consummation 
in virtue, fall behind, and Science, herself, languish for very lack of 
sustenance. 

We expect great help for the present status of biological science from 
Brooks's " Foundations of Zoology." To the question which he imagines 
Aristotle to ask : " Is not the biological laboratory which leaves out the 
ocean and the mountains and meadows a monstrous absurdity ? " this 
department would answer — Yes. And it would add that it is not enough 
to bring our laboratories to the ocean and make fine trips to the mountains 
and the ends of the earth, unless these great factors become a real part of 
the scientific quest. 

In a word, with the so-called discovery and naming of a species of 
animal or plant, and even with its embryonic and adult anatomization, 
biological science has scarcely touched the great problem which the 
species presents. With the half million species of animals and plants of 
which Science has told us scarcely more than the names, Art has stumbled 



Biology. 115 

haltingly along, with all too little help from Science, toward the perfection 
and utilization of a very few, our domesticated species. Even with these 
few the scientific biology of no single one has been adequately worked out, 
and we are practically in the beginnings of scientific studies as to the 
influence of environment in cultural conditions, and as to the possibilities 
for improvement in cross fertilization. Biological science owes to the 
world not only knowledge of the name, form, and structure of a species ; 
it owes as well a clear statement of what the species does, considered as a 
force in nature ; and further, the method by which this force can best be 
utilized. And this is no whit less pure science because incalculable 
human values attach to the knowledge. Biologically we are now at a 
stage comparable from the standpoint of physical science with that of the 
sail-boat and the stage-coach, before science had discovered, and discov- 
ered a way to utilize, the forces of steam and electricity. And we find, 
when we study carefully what one animal or a plant can do, and multiply 
this by the number of individuals in the species, values and magnitudes, 
which we scarcely possess terms to express. Add to the total amounts 
of forces which different species represent, the nicety of adjustment, 
the adaptation of means to ends, the intelligent direction of the forces, 
which make comparative psychology a part of biology, and we begin to 
realize the importance of biology as a science. No seed is too small to 
contain the power, under proper conditions, of covering the world with 
plants of its kind ; and, not only that, but generation after generation it 
may be capable of indefinite improvement. The most minute organisms, 
the bacteria, possess very few interesting features of form or structure 
that we are able to discover, but they have the power to determine the 
ultimate food supply of all animal life, on the one hand ; and, on the other, 
to cause the disease, suffering, and death of untold numbers of animals, 
and even human beings. Insects, on the one hand, have created flowers 
and fruits by their work of cross fertilization, and, on the other, have laid 
a tax on human industries heavier than that of bad government and even 
of war. 

Since the side of function, of the actual work which a species can do, 
presents the greatest ultimate value connected with knowledge of living 
things, if modern biology does not go forward into this great field, its 
whole past history from Aristotle down will be an arrested development. 

The laboratory that undertakes this work must be a unique affair as 
biological laboratories go now. It should have greenhouses, terraria and 



116 Department of 

aquaria, aviaries and inseetories, in order to provide the essential elements 
of normal environment where the life and work of species may be conven- 
iently studied in both their daily rhythms and in their larger life cycles. 
It should especially have easily accessible the actual normal environment 
of the species under investigation, the pond, ocean, stream, grove, forest, 
hill, mountain, field, and garden, where results obtained in the laboratory 
can be readily tested and confirmed in the actual environment of nature. 
In fact, during favorable seasons much of this line of laboratory work 
might well be done out of doors. A laboratory of this kind need not be 
exjjensive, but should consist largely of rooms adapted for individual 
investigators, so that researches upon the life and work of a number of 
different forms may be carried on with the least possible mutual disturb- 
ance and interference. This is an absolute essential to investigations 
of this class. It should also be provided with sunny and sanitarily 
perfect quarters for not only keeping, but rearing and breeding, a con- 
siderable variety of animals. 

These and many other considerations render it imperative, if work 
of the best quality is to be turned out, that a biological laboratory have 
a building of its own. At present this lack has been one of the chief 
obstacles to prosecution of the important lines of work indicated. They 
cannot be successfully studied in rooms used for other purposes, or in a 
building shaken by the running of powerful dynamos and other heavy 
machinery. Natural rhythms and periods of rest and activity may be 
profoundly influenced by these disturbing conditions, and results thus 
largely vitiated. As already stated, the foundations for a biological 
laboratory have been laid, and an inexpensive building would greatly 
facilitate the work of the department. It ought to be erected under 
the idea, now gaining ground, that a laboratory should be a somewhat 
temporary building, which could be altered and reconstructed from time 
to time as new problems arise. 

The matter of biological nature study has already been referred to, 
and it is the opinion that such a research laboratory should be in 
organic relationship with elementary education and the public school. 
It is believed that this side of nature, the side of movement and activity, 
is the natural side of approach for the child. It is peculiarly akin to 
that animism of childhood which projects life and action even into 
inanimate things. It is this side of living nature, which, from its 
intrinsic fascinations and varied affinities with the passionate activity 



Biology: 117 

of child life, is calculated to create enduring love of nature ; and the 
vast human values and interests connected with it constitute the most 
natural wellspring for love of science. 

In line with this idea, two nature-study leaflets have already been 
printed, upon, respectively, the " Biology of the Common Toad " and the 
"Biology of Our Common Birds." Both of these were written by Dr. 
Hodge, and he has thus far assumed all financial responsibility for their 
publication. He also has in course of preparation similar studies on a 
series of biological subjects, insects, fishes, and reptiles, flowers, fruit, 
and forest trees, bacteria and moulds, and a few others, which will 
provide ample materials for nature study from the standpoint above 
indicated for the entire school course. On the one hand, such connection 
between the biological laboratory and the schools will furnish channels 
for the distribution of information to the public, and, on the other, may 
be made to supply, not only stimulus, but assistance to its work as well. 

Bacteriology is a recently created department of biology which has 
claimed recognition as an independent science by reason of its wonder- 
ful development since about 1880, when the discoveries of Koch, Pasteur, 
and Lister revealed the causal relations which exist between these 
minute organisms and disease. We can express the enormous values 
of scientific knowledge of these germs only in terms of human life itself. 
And it is a worthy refutation of the charge sometimes brought against 
science that it disregards the welfare of humanity that, as Professor 
Ludwig said, laboratories devoted to other lines of biological work 
have been depopulated, because their students have flocked into this 
new and important field. The bacteria are coming to be recognized as 
one of the most, if not the most, important element in the environment 
of animal and even plant species ; hence their consideration is essential 
in such studies as have been outlined above, which aim to determine 
the influence of environmental conditions upon the activity, health, and 
vigor of species. Still the pathological side will not be able long to 
dominate the science of biology ; and even with relation to diseased 
conditions, the side of normal function, physiology proper, must remain 
preeminent. In fact, it may even now be stated as the highest contri- 
bution of bacteriology, that it has revealed the fact that the highest 
possible health level is the best practical safeguard against inroads of 
microbic disease. Still the great importance of the subject has made it 
cause for regret that the resources of the department have not permitted 



118 Department of Biology. 

the establishment of a well-equipped bacteriological laboratory. The 
next step in the development of the department should be in this 
direction. 

The library of the biological department has been selected with a 
view to making it the best possible working library for those engaged in 
biological research. 



THE DEPARTMENT OF PSYCHOLOGY. 

By Edmund Clark SAjrroED. 

PAST AND PRESENT STAFF, i 

G. Stanley Hall, Ph.D., LL.D., President of the University and Professor 
of Psychology and Education since 1889. 

Henry H. Donaldson, Ph.D., Assistant Professor of Neurology, 1889-92. 

Clifton F. Hodge, Ph.D., Assistant in Psychology, 1890-91 ; Assistant Pro- 
fessor of Physiology and Neurology since 1892. 

Edmund C. Sanford, Ph.D., Instructor in Psychology, 1889-92; Assistant 
Professor of Psychology since 1892. 

William H. Burnham, Ph.D., Decent in Pedagogy, 1890-92 ; Instructor in 
Pedagogy since 1892. 

Benjamin Ives Gilman, Instructor in Psychology, 1892-93. 

Alexander F. Chamberlain, Ph.D., Lecturer in Anthropology since 1892. 

Franz Boas, Ph.D., Docent in Anthropology, 1889-92. 

B. C. Burt, A.M., Docent in Philosophy, 1889-90. 

Alfred Cook, Ph.D., Docent in Philosophy, 1889-90. 

Herman T. Lukens, Ph.D., Docent in Pedagogy since 1895. 

Arthur MacDonald, A.M., Docent in Ethics, 1889-91. 

Adolf Meyer, M.D., Docent in Psychiatry since 1896. 

Charles A. Strong, Docent in Philosophy, 1890-91. 

FELLOWS AND SCHOLARS. 

H. Austin Aikins, Ph.D., Fellow in Psychology, 1892-93 ; Honorary FeUow, 

1893-94. 
Ernest Albee, Scholar in Psychology, 1889-90 ; Fellow, 1890-91. 
Arthur Allin, Ph.D., Honorary Fellow in Philosophy, 1896-96. 
N. P. Avery, Scholar in Psychology, 1895-96. 
Thomas P. Bailey, Jr., Ph.D., Fellow in Psychology, 1892-93. 

1 As this list shows, the Department of Psychology has included, Anthropology, Crimin- 
ology, Neiirology, Psychiatry, Education, and Philosophy. The report of work in Neurology 
has been incorporated by Dr. Hodge with that in Physiology and Biology. 

119 



120 Department of 

Henry E. Bakee, Student in Psychology, 1894-95 ; Fellow, 1895-96 ; Honor- 
ary Fellow, 1896-97, and 1898-99. 

John A. Bergsteom, Fellow in Psychology, 1891-94. 

Eugene W. Bohannon, Scholar in Pedagogy, 1895-96 ; Fellow in Psychology, 
1896-98. 

Fkedekick E. Bolton, Honorary Fellow in Psychology, 1897-98. 

Thaddeus L. Bolton, Scholar in Psychology, 1890-91 ; Fellow, 1891-93. 

Eenest N. Brown, Scholar in Psychology, 1891-92. 

Elmer B. Bryan, Scholar in Philosophy, 1898-99. 

William L. Bryan, Fellow in Psychology, 1891-93. 

Frederic Buek, Scholar in Psychology, 1896-97 ; Honorary Fellow, 1897-98. 

Will G. Chambers, Scholar in Psychology, 1897-98. 

Walter Channing, Honorary Scholar in Psychology, 1889-90; Honorary 
Fellow, 1890-92. 

OscAE Chrisman, Fellow in Pedagogy, 1892-94. 

Eobebt Clark, Scholar in Pedagogy, Jan., 1898-June, 1899. 

Charles W. Clinton, Fellow in Psychology, 1897-98. 

Feedeeick W. Colegeove, Honorary Fellow in Psychology, 1896-99. 

Thomas E. Ceoswell, Scholar in Pedagogy, 1895-97. 

Heney S. Cuetis, Fellow in Psychology, 1895-97. 

Aethue H. Daniels, Fellow in Psychology, 1892-93. 

Geoege E. Dawson, Fellow in Psychology, 1895-97. 

Fletchee B. Deesslae, Scholar in Psychology, 1891-93 ; Fellow, 1893-94. 

Feank Drew, Scholar in Psychology, 1892-93; Fellow, 1893-95. 

Frederick Eby, Scholar in Pedagogy, 1898-99. 

Stafford C. Edwards, Scholar in Pedagogy, 1897-98. 

A. Caswell Ellis, Scholar in Pedagogy, 1894-95 ; Fellow in Psychology, 
1895-97. 

H. L. Everett, Scholar in Psychology, 1896-97 ; Honorary Fellow, 1897-98. 

Daniel Folkmae, Fellow in Psychology, 1889-90. 

Clemens J. Feanoe, Scholar in Psychology, 1898-99. 

J. Iewin France, Scholar in Psychology, 1896-97. 

Alexandee Eraser, Fellow in Psychology, 1891-92. 

John P. Fruit, Scholar in Psychology, 1891-92. 

Henry H. Goddard, Scholar in Psychology, 1896-97 ; Fellow, 1897-99. 

Cephas Guillet, Scholar in Psychology, 1895-96 ; Fellow, 1896-98. 

John A. Hancock, Fellow in Pedagogy, 1893-94. 

S. B. Haslett, Scholar in Psychology, 1898-99. 

Clark W. Hetherington, Fellow in Psychology, 1898-99. 

tE. C. Hollenbaugh, Ph.D., Scholar in Psychology, 1892-93. Died July 6, 1893. 

William A. Hoyt, Scholar in Pedagogy, 1893-94. 

Edmund B. Huey, Scholar in Psychology, 1897-98; Fellow, 1898-99. 

D. D. Hugh, Fellow in Psychology, 1895-96. 

John P. Hylan, Fellow in Psychology, 1895-97. 



Psychology. 121 

TiLMON Jenkins, Scholar in Pedagogy, 1897-98. 

George E. Johnson, Scholar in Pedagogy, 1893-94 ; Fellow, 1894-95. 

E. A. KiEKPATEicK, Scholar in Psychology, 1889-90 ; Eellow, 1890-91. 

Milton S. Kistlee, Scholar in Pedagogy, 1897-98. 

Linus W. Kline, Scholar in Psychology, 1896-97 ; Eellow, 1897-98 ; Honorary 

Eellow, 1898-99. 
William 0. Keohn, Ph.D., Eellow in Psychology, March-June, 1892. 
E. G. Lancastee, Scholar in Psychology, 1895-96 ; Fellow, 1896-97. 
James S. Lemon, Scholar in Psychology, 1891-93 ; Student, 1893-94. 
James E. Le Rossignol, Ph.D., Pellow in Psychology, May-July, 1892. 
James H. Leuba, Scholar in Psychology, 1892-93 ; Fellow, 1893-95 ; Honorary 

Fellow, 1895-96. 
Eenest H. Lindley, Fellow in Psychology, 1895-97. 
Geoege W. a. Luckey, Fellow in Psychology, 1894-95. 
Fkank H. McAssey, Scholar in Psychology, 1898-99. 
Geoege F. Metzlee, Ph.D., Fellow in Psychology, 1891-92. 
Dickinson S. Millee, Fellow in Psychology, 1889-90. 
Hbebeet Nichols, Fellow in Psychology, 1889-91. 
C. A. Oee, Scholar in Psychology, 1889-90. 
Geoege E. Parteidge, Special Student in Philosophy, 1895-96; Scholar in 

Psychology, 1896-98 ; Fellow, 1898-99. 
T. RicHAED Peede, Special Student in Philosophy and Pedagogy, 1895-96 ; 

Honorary Scholar in Philosophy, 1896-97. 
Daniel E. Phillips, Scholar in Psychology, 1894^March, 95 ; Honorary Scholar, 

Jan.-June, 97 ; Fellow, 1897-98. 
Jeffeeson R. Pottee, Scholar in Pedagogy, 1890-91. 
J. 0. QuANTZ, Ph.D., Honorary Fellow in Psychology, 1897-98. 
J. F. EiEGAET, Scholar in Psychology, 1890-91. 
EoBEET J. EiCHAEDSON, Fellow in Psychology, 1898-99. 
Eewin W. Eunkle, Ph.D., Honorary Fellow in Psychology, Jan.-June, 1899. 
Albeet Schinz, Ph.D., Honorary Fellow in Psychology, 1897-98. 
Alva E. Scott, Honorary Scholar in Psychology, 1894-95; 1896-97. 
Colin A. Scott, Fellow in Psychology, 1894-96. 

E. W. Sceiptuee, Ph.D., Fellow in Psychology, Jan.-June, 1891 ; 1891-92. 
Chaeles H. Seaes, Ph.D., Honorary Fellow in Pedagogy, 1897-99. 
Albeet E. Segswoeth, Honorary Fellow in Psychology, 1893-94. 
John C. Shaw, Scholar in Pedagogy, 1895-96; Fellow in Psychology, 1896-97. 
Heney D. Sheldon, Fellow in Pedagogy, 1897-99. 

Feedeeic D. Sheeman, Ph.D., Honorary Fellow in Psychology, 1898-99. 
TosHiHiDB Shinoda, Honorary Scholar in Pedagogy, 1889-90. 
Maueice H. Small, Scholar in Psychology and Pedagogy, 1895-96 ; Fellow in 

Psychology, 1896-98. 
WiLLAED S. Small, Scholar in Psychology, 1897-98 ; Fellow, 1898-99. 
Feank E. Spaulding, Ph.D., Honorary Fellow in Psychology, 1894-95. 



122 Department of 

Edwin D. Staebuck, Fellow in Psychology, 1895-97. 

J. EicHAED Street, Scholar in Pedagogy, 1895-96; Fellow in Psychology, 

1896-98. 
Charles H. Thurbee, Honorary Fellow in Pedagogy, Jan.-April, 1899. 
Frederick Tract, Fellow in Psychology, 1892-93. 
Norman Teiplett, Fellow in Psychology, 1898-99. 

Geeald M. West, Ph.D., Fellow in Anthropology, 1890-91 ; Assistant, 1891-92. 
Guy M. Whipple, Scholar in Psychology, 1897-98. 
MiNosuKB Yamaguchi, Scholar in Psychology, 1897-98. 
Albert H. Yoder, Scholar in Pedagogy, 1893-94. 
Lewis E. York, Scholar in Pedagogy, 1897-98. 



HISTORICAL SKETCH OF THE WORK IN GENERAL PSYCHOLOGY. 

The ten years covered by the history of the Psychological Depart- 
ment in this University have been eventful in the history of Psycho- 
logical Science in the country at large. 

Before 1880 the science was taught as a stepping-stone to metaphysics 
and ethics ; its method was chiefly introspective ; laboratories were 
unheard of; and genetic and comparative psychology were a terra 
incognita. During the early part of the eighties, however, the idea 
that psychology was an independent science, to be advanced by experi- 
ment and systematic observation, was gradually taking root, and in 
1888 and 1889 began a vigorous growth. New interest was taken 
in the subject, laboratories began to be opened, and a special journal 
was started for the publication of psychological investigations (TAe 
American Journal of Psychology'). Since that time the interest has 
continued; the laboratories have increased at the rate of three or 
four a year till they now number between thirty and forty, are found 
in almost all the leading universities of the country, are often liberally 
supported, and in some cases surpass the best European laboratories 
in equipment ; and many workers trained at home and abroad have 
entered the field. In 1892 the American Psychological Association 
was started, and now numbers over one hundred members, nearly all 
actively interested in psychological teaching or investigation. A little 
later genetic and comparative psychology appeared in an awakened interest 
in the study of childhood; and more recently still have been extended 



Psychology. 123 

into a new and fruitful study of the mind and habits of animals. 
Since 1894 a second psychological journal, The Psychological Review, 
has been published; and many articles of psychological interest appear 
in the Pedagogical Seminary (especially on Child Study) and in the 
other educational magazines. It is with such a period of vigorous 
interest in psychology and of rapid growth in facilities that our own 
ten years' history coincides. 

In turning now to this more particularly, I shall speak first of 
the work in experimental psychology, which, though by no means 
the whole of the new movement, has been so far rather its centre and 
characteristic mark, and afterward of that of a more general character. 

The distinctive feature of American laboratories generally is the 
extent to which they are used for psychological teachmg as distinct 
from psychological investigation. Both foreign and home laboratories 
have the double purpose of instruction and research, but in the American 
laboratories a little greater emphasis seems to be laid on their pedagogical 
usefulness. This emphasis is doubtless due in part to more deep- 
seated differences between American and foreign universities, but it 
has been favored also by the feeling that a general acquaintance with 
laboratory problems and methods should precede the undertaking of 
original investigation. In the case of the Clark laboratory, it has 
been further enforced by the number of students of pedagogy for whom 
a psychological groundwork must be provided. 

The advantage of laboratory teaching of psychology is that of all 
proper laboratory teaching, namely, that the student is brought face 
to face with that about which he is studying, and knows the thing 
itself at first hand rather than what some text-book or lecturer may 
say about it. For those who intend to take up experimental investi- 
gation later, it is of course the natural apprenticeship. 

Such elementary laboratory teaching demands some sort of manual 
or guide that can be put into the hands of the students, a fact that 
became painfully evident in the first years of the department ; and as 
at the time none whatever existed, it was necessary to make one. A 
beginning was made with manuscript sheets struck off on the mimeo- 
graph. Later these were worked over in part in a series of articles in the 
Journal of Psychology, and, finally, again revised and enlarged, this part 
was regularly published, six chapters in 1894, and the remainder last year, 
making altogether a volume of about 450 pages covering the topics of 



124 Department of 

sensation and perception. This work seems to have supplied a genuine 
need — at least, has met with a wide acceptance in American laboratories. 
Up to the year just passed the laboratory course has not extended 
beyond the usual laboratory topics of sensation and perception, reaction- 
times, Weber's law, and the like. But, beginning with the year 1898-99, 
an important enlargement was made by the addition of laboratory 
practice in comparative psychology. Under the special guidance of 
Dr. Kline, opportunities have been given for the study of the habits 
and mental life of a number of more or less typical animals. Starting 
with the microscopical amceba, paramecium, and vorticella, the list has 
been extended upward to include earthworms, slugs, fish, chickens, 
white rats, and kittens. Though lectures have been regularly delivered, 
demonstrations made, and seminaries held in connection with the labora- 
tory work, the development of this practice course in both experimental 
and comparative psychology, together with the manual mentioned and 
the similar though briefer work of Dr. Kline, is regarded as the most 
important product of the Clark laboratory on its teaching side. 

The scientific work of the laboratory has resulted in ten or twelve 
extended researches and in a considerable number of briefer studies. It 
is not easy in short space to give an intelligible account of studies upon a 
variety of topics so considerable as these have covered, but it has seemed 
to the writer that a list of the titles of papers published, with a few 
lines of explanation where necessary, might serve the purpose. 

STUDIES FROM THE PSYCHOLOGICAL LABORATORY. 
Time and Rhythm. 

Nichols : The Psychology of Time. Am. Jour, of Psy., Vol. 3, pp. 
453-529, and Vol. 4, pp. 60-112 (1891). (Dissertation.) Repub- 
lished in book form by Henry Holt, New York, 1891. 

A general discussion of the time problem. The experimental portion 
shows that a period of practice in keeping time at a slow rate tends to 
slow a quicker rate tried immediately afterward, and vice versa, thus 
demonstrating a dependence of time j adgments upon artificially acquired 
rhythms. 

Bolton, T. L. : On the Discrimination of Groups of Rapid Clicks. 
Ibid., Vol. 5, pp. 294-310 (1893). 

An indirect determination of the fineness of discrimination for very 
short periods of filled time. 



Psychology. 125 

Bolton, T. L. : Rhythm. Ibid., Vol. 6, pp. 145-238 (1894). (Dis- 
sertation.) 

A general account of the subject. The experimental portion deals 
■with the subjective rhythms observed in uniform series of sounds, and 
with the structure of the rhythmic feet vi^hich result when sounds of 
different length or intensity are regularly introduced in an otherwise 
uniform series. 

Hamlin, Alice J. : On the Least Observable Interval between Stimuli 
addressed to Disparate Senses and to Different Organs of the Same 
Sense. lUd., Vol. 6, pp. 564-575 (1895). 

Experimental determination of the interval that must separate nearly 
simultaneous sensations in order that their order may be recognized. 
Experiments with clicks and flashes, flashes and shocks, separate clicks 
heard by the two ears, etc., and with indifferent and with specially 
directed attention. 

Whipple : On Nearly Simultaneous Clicks and Flashes. Ibid., Vol. 
10, pp. 280-286 (1899). 

A study of the reason for the difference between the results of 
Dr. Hamlin and of earlier European observers in the matter of which 
order of stimuli (click-flash or flash-click) could be more readily recog- 
nized. Dr. Hamlin's results are confirmed and the difference proved not 
to lie in the fact that the European observers had made use of series of 
pairs of clicks, which had been supposed a possible cause. 

Memory. 

Bolton, T. L. : The Growth of Memory in School Children. Ibid., 
Vol. 4, pp. 362-380 (1892). 

A study by the memory-span method on upwards of fifteen hundred 
children, made in connection with the anthropometric studies of Dr. 
Boas, together with a theoretical treatment of the statistical curves 
obtained. 

Bergstrom : Experiments upon Physiological Memory by Means of 
the Interference of Associations. Ibid., Vol. 5, pp. 356-869 
(1893). 

The Relation of the Interference to the Practice Effect of an 
Association. Ibid., Vol. 6, pp. 433^42 (1894). 

An Experimental Study of Some of the Conditions of Mental 



126 Department of 

Activity. Ibid., Vol. 6, pp. 247-274 (1894). (These three papers 
were united to form a Dissertation.) 

A pack of eighty cards (eight cards each of ten different kinds) is sorted 
according to the kinds, and after an interval re-sorted, but with such an 
arrangement that each kind occupies a different place on the table. The 
second sorting takes longer because of interference between the new as- 
sociations and those formed in the first sorting, and the excess of time 
required measures indirectly the persistence of the first set of associa- 
tions. The first paper gives curves showing the rate of falling away of 
the first associations (curves of forgetting) determined by this method. 
The second paper, by an ingenious application of the same method, 
shows that the interference power of any association is practically equal 
to the fixity given it by practice, — in other words, " that the work of 
breaking up a habit is roughly proportional to the work of forming it." 
The third paper gives determinations of the variations in mental abil- 
ity during the work hours of the day made upon several different sub- 
jects and with different sorts of tests. 

Daniels: The Memory After-image and Attention. Ihid., Yo\. 6, 
pp. 558-564 (1895). 

The aim was to measure the native persistence of bare impressions 
as distinguished from that which they show when received with atten- 
tion and held by association. The time was found to be very short, not 
more than five or ten seconds. 

Smith, Theodate L. : On Muscular Memory. Ihid., Vol. 7, pp. 
453-490 (1896). 

A painstaking comparative study of the memory of nonsense syl- 
lables learned with and (as far as possible) without the cooperation of 
the vocal mechanism. The memory assisted by even incipient move- 
ments was, in all cases, distinctly better, — a result further confirmed 
by a similar study on various combinations of the manual signs of the 
deaf-mute alphabet learned with and without execution of the hand 
postures involved. 

Colegbove: The Time required for Recognition. Ihid., Vol. 10, 
pp. 286-292 (1899). 

A chronoscopic study of the time required for deciding whether a 
picture suddenly presented had been seen before or not. 



Psychology. 127 

Psychology of Movement. 

Bryan, W. L. : On the Development of Voluntary Motor Ability. 
Ihid., Vol. 5, pp. 125-204 (1892). (Dissertation.) 

A study of the rate, precision, and strength of voluntary movements 
in the case of adults, and of a large number of school children from six 
to sixteen years old. Differences due to fatigue, to increasing age, to 
sex, to bilateral asymmetry, and the like, are carefully worked out ; the 
mathematical treatment of the statistics (thanks in part to suggestions 
from Dr. Boas) is unusually full and rigid. 

Reigakt and Sanfokd: On Reaction-times when the Stimulus is 
Applied to the Reacting Hand. Ibid., Vol. 5, pp. 351-355 
(1893). 

The experiments bring into question the statement of Exner that 
reactions are slower when the stimulus is applied to the reacting hand. 

Hancock: A Preliminary Study of Motor Ability. Pedagogical 
Seminary, Vol. 3, pp. 9-29 (1894). 

The Relation of Strength to Flexibility in the Hands of Men 
and Children. Ihid., Vol. 3, pp. 308-313 (1895). 

The first is a study of the spontaneous movements of school children 
from five to seven years old, — of the swayings and tremors displayed 
in efforts to stand still with eyes open or closed, or to hold the hand or 
forefinger still, — movements analogous to those of nervous disease. The 
second paper shows for the persons tested (20 men, 22 boys, and 11 
girls), greater flexibility in the hands of the men as measured by the 
extent to which the joints could be flexed voluntarily. Both papers are 
of avowedly pedagogical interest. 

Lancaster : Warming Up. Colorado College Studies, Vol. 7, pp. 
16-29 (1898). 

Based upon ergographic experiments. 

Sensation and Perception. 

ScRrPTTJRE : Einige Beobachtungen iiber Schwebungen und Differenz- 
tone. PUlos. Studien, Vol. 7, pp. 630-632 (1892). 

A brief experimental study of beats and difference tones produced by 
forks sounding separately on either side of the head. 



128 Department of 

Dresslar : On the Pressure Sense of the Drum of the Ear and " Fa- 
cial Vision." Am. Jour, of Psy., Vol. 5, pp. 344-350 (1893). 

The study shows that the faculty of the blind of recognizing the 
presence or absence of neighboring objects, which has been credited to 
some sort of obscure visual sensation in the skin of the face, or to sen- 
sations of pressure mediated by the drum of the ear, is probably a 
matter of hearing. 

Krohn : An Experimental Study of Simultaneous Stimulation of the 
Sense of Touch. Journal of Nervous and Mental Disease, N. S., 
Vol. 18, pp. 169-184 (1893). 

Based chiefly on experiments made in the Clark laboratory. 

Letjba: a New Instrument for Weber's Law, with Indications of a 
Law of Sense Memory. Am. Jour, of Psy., Vol. 5, pp. 370-384 
(1893). 

Weber's law demonstrated in the classification of artificial stars. 
The law of sense memory suggested is that memories of intensities of 
sensation tend to shift toward the middle of the usual scale of intensities. 

Dresslar : A New Illusion for Touch and an Explanation for the 
Illusion of Certain Cross Lines in Vision. Ibid., Vol. 6, pp. 
275-276 (1894). 

This illusion is similar to that of the Poggendorif illusion in vision, 
and the obvious explanation in the case of the touch illusion is extended 
to the visual one. 

Sanford: a New Visual Illusion. Science, Feb. 17, 1893. 
A visual illusion involving false judgments. 

Dresslar : Studies in the Psychology of Touch. Am. Jour, of Psy., 
Vol. 6, pp. 313-368 (1894). (Dissertation.) 

The study is in three sections : 1. On the Education of the Skin with 
the jEsthesiometer, particularly of its bilateral effects ; 2. Experiments 
on Filled and Open Space for Touch, showing that filled space seems 
larger when the finger moves over it, or when the extents compared are 
moved under the resting finger ; 3. On Apparent Weight as affected by 
Apparent Size and Shape — tests upon school children and adults. 



Psychology. 129 

Circulation and Respiration. 

Dawson : Effects of Mental States upon Circulation. 

(Records in tlie instructor's hands but not worked up as yet.) 
Preliminary note in the Proc. of the Am. Psychological Ass'n, 
Psychological Review, Vol. 4, pp. 119-121 (1897). 

An extended study made with the plethysmograph applied simultane- 
ously to the hand and eye. 

Whipple : The Influence of Forced Respiration on Psychical and 
Physical Activity. Am. Jour, of Psy., Vol. 9, pp. 560-571 (1898). 

The effect of very rapid breathing on eight simple tasks involving 
sensory or motor activities, or both. Effects slight in most cases ; 
physical strength and endurance seem to be increased, while discrimi- 
native powers seem to be depressed. 

Comparative Psychology. 

Kline: Methods in Animal Psychology. Ibid., Vol. 10, pp. 256-279 
(1899). 

Discussion of methods, and presentation of the results of experiments 
upon vorticellse, wasps, chicks, and white rats. 

Small, W. S. : Notes on the Psychic Development of the Young 
White Rat. Ibid., Vol. 11, pp. 80-100 (1899). 

The study consists of a careful record of the bodily and mental 
development of the white rat from birth onward for a number of weeks. 

Studies on Miscellaneous Topics. 

Calkins, Mary Whiton : Statistics of Dreams. Ibid., Vol. 5, pp. 
311-343 (1898). 

A careful analytical and statistical study of dreams, recorded immedi- 
ately after waking by two subjects during a period of six or eight 
weeks. An effort to get as full a picture as possible of normal dream- 
life. 

LucKEY : Some Recent Studies of Pain. Ibid., Vol. 7, pp. 108-123 
(1895). 

A review of recent literature on the physiology and psychology of 
pain. 



130 Department of 

Miles, Caroline: A Study of Individual Psychology. Ibid., Vol, 
6, pp. 534-558 (1895). 

A questionnaire study of a number of special points, made on one 
hundred students in Wellesley College. Such topics are considered as : 
How do you know your right hand from your left ? How do you con- 
centrate attention ? Fears as children ? Things causing anger ? Favor- 
ite color? Earliest memories? Early ideals? etc. (This study and 
the preceding, though not experimental, were made in connection with 
the work of the laboratory.) 

Drew: Attention: Experimental and Critical. Ibid., Vol. 7, pp. 
533-576 (1896). (Dissertation.) 

The experimental portion of this paper consists of three sections : 

1. Eeaction and Association Times with Differing Degrees of Distraction ; 

2. A Qualitative Study of Associations with Full and with Distracted 
Attention; 3. A Study of the Apparent Order of nearly Simultaneous 
Stimuli with variously Directed Attention. 

Hylan : The Fluctuation of Attention. Psychological Review, Mono- 
graph Supplement, No. 6, pp. 1-78 (1898). 

An experimental and expository paper, the experiments approaching 
the question in several different ways. 

HuBY : Preliminary Experiments in the Physiology and Psychology 
of Reading. Am. Jour, of Psy., Vol. 9, pp. 576-586 (1898). 

Tests of rate of reading in vertical and horizontal directions, of the 
importance for recognition of the first and last parts of words, and of 
the actual movements of the eye in reading, determined by apparatus 
attached to the eye. This study was continued during the year 1898-99, 
with results that are nearly ready for publication. 

Technical Matters. 

The following papers have been chiefly concerned with technical 
matters and apparatus. 

SCKIPTUEE : Psychological Notes. Ibid., Vol. 4, pp. 577-584 (1892). 

On the method of regular variation ; The least perceptible variation 
in pitch; The faintest perceptible sound ; Notation for intensity ; A con- 
stant blast for acoustical purposes ; Some psychological terms. 

ScEiPTUEB : An Instrument for Mapping Hot and Cold Spots on the 
Skin. Science, Vol. 19, p. 258 (1892). 



Psychology. 131 

Dkesslab: a New and Simple Method for comparing the Perception 
of Rate of Movement in the Direct and Indirect Fields of Vision. 
Am. Jour, of Psy., Vol. 6, p. 312 (1894). 

Sajstfoed: a Simple and Inexpensive Chronoscope. Ibid., Vol. 3, pp. 
174-181 (1890). 

A New Pendulum Chronograph. Ibid., Vol. 5, pp. 384-389 
(1893). 

Some Practical Suggestions on the Equipment of a Psychologi- 
cal Laboratory. Ibid., Vol. 5, pp. 429-438 (1893). 

Notes on New Apparatus. Ibid., Vol. 6, pp. 575-584 (1895). 

The Vernier Chi-onoscope. Ibid., Vol. 9, pp. 191-197 (1898). 



While these studies have been going on in the laboratory, the work 
in philosophy and education, and in the non-laboratory sections of 
psychology, has been carried forward with perhaps even greater vigor. 
President Hall, Dr. Burnham, Dr. Boas, Dr. Chamberlain, Dr. Meyer, 
Messrs. MacDonald, Strong, Gilman, and others, have lectured on various 
aspects of the history of philosophy, pedagogy, psychiatry, aesthetics, 
criminology, and anthropology. Some account of the work in education, 
anthropology, and psychiatry will be found below in the special reports 
of Drs. Burnham, Chamberlain, and Meyer; the rest will be spoken of 
here. 

The work of instruction has been carried on by means of seminaries as 
well as lectures, and to a great extent also in the more informal but most 
effective way of personal conference with individual students. 

It is not possible from data now at hand to give a complete list of the 
courses given by President Hall, but at different times he has lectured 
upon the History of Philosophy, Ancient, Mediaeval, and Modern (taking 
philosophy in a sense wide enough to include psychology, education, and 
medicine) ; on Cosmology, on General Psychology, on Morbid Psychology 
(with clinics at the Worcester Lunatic Hospital), on Genetic Psychology 
(both in the animal series and in the child), Educational Philosophy and 
Practice, Child Study, Adolescence, Curricula, Teaching of Special Sub- 
jects, and upon other pedagogical topics. In addition to these lectures, 



132 Department of 

President Hall has, almost from the first, conducted a weekly seminary, 
meeting in the evening at his own house. Here members of the depart- 
ment have reported on the progress of their investigations and received 
the benefit of mutual criticism, or have united in the study of some 
special author or topic. Notes of the discussions of the seminary during 
a period when chief attention was given to Plato have been published by 
Dr. H. Austin Aikins in the Atlantic Monthly (September and October, 
1894), under the title, "From the Reports of the Plato Club." Presi- 
dent Hall has also directed the research of the greater part of the men 
in the department, recommending topics, methods, literature, and lines of 
thought, and in some cases has gone so far as to enter into joint author- 
ship with the students, taking their incomplete results and putting them 
into shape for publication. 

In the first years after the opening of the University, President Hall 
was assisted in the philosophical teaching by Dr. Alfred Cook, Dr. B. C. 
Burt, and Mr. C. A. Strong as Docents. During the year 1889-90, Drs. 
Burt and Cook gave courses on Greek philosophy and on modern philos- 
ophy from Locke to Kant; and in 1890-91, Mr. Strong gave a brief course 
on the history of psychology among the Greeks from Thales to Aristotle, 
— an abstract of the lectures being later published in the American Jour- 
nal of Psychology, Vol. 4, pp. 177-197 (1891). During 1892-93, Mr. Ben- 
jamin Ives Gilman, as Instructor in Psychology, lectured on Pleasure and 
Pain, and pursued independent investigations on the theory of musical 
consonance. Abstracts of his lectures are to be found in the American 
Journal of Psychology, Vol. 6, pp. 1-60 (1893). Mr. Arthur MacDonald, 
as Docent in Ethics, devoted himself to theoretical and practical studies 
in criminology, lecturing on that topic during the first year of the 
University and conducting a seminary, with occasional lectures, during 
the second. Since 1891 all the philosophical teaching of the department 
has been done by President Hall himself. 

The research of this section of the psychological department has been 
devoted for the most part to questions that are too large and too unman- 
ageable for successful treatment in the laboratory, — questions of the 
origin and development of mental life in the race and in the child, of 
adolescence and sex, of emotion, of religion, and the like. Its scope and 
nature will be apparent from the following list of studies: — 



Psychology. 133 

Child study and Psychogenesis. 

Tracy : The Language of Childhood. Am. Jour, of Psy., Vol. 6, pp. 
107-138 (1893). 

The Psychology of Childhood. Boston, 1893. 94 pp. (Includes 
a reprint of the preceding.) (Dissertation.) 

The first paper is a careful study of extant data on the physiology, 
phonetics, and psychology of infant language, together with new mate- 
rial gathered by the author. The second is a similar treatment of 
sensation, emotion, intellection, and volition as they appear in very 
young children. 

Shaw : A Test of Memory in School Children. Pedagogical Semi- 
nary, Vol. 4, pp. 61-78 (1896). 

An account of tests made with a carefully prepared story, which was 
read to the children to test memory and lines of greatest interest. 
Statistics of about seven hundred papers from children ranging from the 
third year of school life to those in the higher classes of the high school. 

Hall and Ellis: A Study of Dolls. Ihid., Vol. 4, pp. 129-176 
(1896). 

A study of the various aspects of the interest in dolls and of ways in 
which they are used in play, based upon numerous replies to two ques- 
tionnaires. 

Small, M. H. : The Suggestibility of Children. Ihid., Vol. 4, pp. 
176-220 (1896). 

A record of experiments both on groups of children and on separate 
individuals, together with a large number of returns from a question- 
naire, with pedagogical inferences and applications. 

Curtis : Inhibition. Ihid., Vol. 6, pp. 65-113 (1898). (Dissertation.) 

The four sections of the paper present : 1. A Summary of Facts and 
Theories, Psychological, Biological, and Neurological ; 2. An Account of 
the Influence of Different forms of Activity on one Another ; 3. A Study 
of Eestlessness in Children ; and 4. Pedagogical Inferences from the Fore- 
going. The third section gives results of experiments and observations 
by the author together with questionnaire returns. The term " inhibition" 
is taken in a very wide sense. 

Partridge: Reverie. Ihid., Vol. 5, pp. 445-474 (1898). 

A study of 337 questionnaire returns on day dreams and related phe- 
nomena. The physical signs, the subjective state, the causes and condi- 



134 Department of 

tions, the content, and the awakening are considered. An appendix 
contains records of the efforts of 330 children to describe an imaginary 
animal, and of an attempt to gather statistics as to hypnagogic images 
from upward of 800 children. 

Dawson : A Study of Youthful Degeneracy. Ihid., Vol. 4, pp. 
221-258 (1896). 

A careful study of about 60 degenerate youths (including 26 boys 
and 26 girls from the state reform schools of Massachusetts) as to 
Vitality, Head and face configuration, Anomalies of physical structure, 
Keenness of senses, Intellectual ability. Parentage, and Environment. 

Hall: Some Aspects of the Early Sense of Self. Am. Jour, of Psy., 
Vol. 9, pp. 351-395 (1898). 

A study of the growth and development of self-consciousness based 
on questionnaire returns. Making acquaintance with hands, feet, and 
other parts of the body, external and internal ; influence of dress 
and adornment ; experiences with mirrors ; various pet names ; childish 
conceptions of the soul ; questionings of children about their own identity, 
present reality, etc.; the effect of social environment, beginning espe- 
cially with the mother. 

Psychology of Religion. 

Daniels: The New Life: a Study of Regeneration. Ibid., Vol. 6, 
pp. 61-106 (1893). (Dissertation.) 

A study of adolescence in its anthropological and psychological as- 
pects, with special reference to conversion and other religious experi- 
ences occurring at that period, the whole being an effort to show the 
means by which the fundamental truths of religion and theology may be 
restated in accord with science and life. 

Leuba : A Study of the Psychology of Religious Phenomena. Ibid., 
Vol. 7, pp. 309-385 (1896). (Dissertation.) 

Based upon noted cases of conversion found in religious literature, on 
material gathered by questionnaire and in personal interviews. The 
headings of the first part are: The religious motive. Analysis of con- 
version. Sense of sin, Self-surrender, Faith, Justification, Joy, Appear- 
ance of newness. The second part treats of the current doctrines of 
justification, faith, will, determinism, and the doctrine of the grace of 
God as related to the experiences described. An appendix contains a 
number of the cases in full. 



Psychology. 135 

Starbuck: a Study of Conversion. Ihid., Vol. 8, pp. 268-308 
(1897). 

Contributions to the Psychology of Religion : Some Aspects of 
Religious Growth. JSi'c^., Vol. 9, pp. 70-124(1897). (Dissertation.) 

The first paper is a study of sudden conversions ; the second of more 
gradual changes of a similar character. Both are based almost exclu- 
sively on questionnaire returns ; the first on 137 cases, the second on 195. 
The topics in the first paper are : Age of conversion, Motives and forces 
leading to conversions. Experiences preceding conversion, The change 
itself, Postconversion phenomena, Other experiences similar to conver- 
sion, General view of conversion. Those of the second paper are: 
Statistics of material. Adolescent phenomena. The period of reconstruc- 
tion, External influences. Cases without marked stages of growth, Adult 
religious consciousness. Ideals, Significance of the facts. 

Leuba : The Psycho-physiology of the Moral Imperative. Ihid., 
Vol. 8, pp. 528-559 (1897). 

An analysis of the phenomena of conscience, together with argument 
to show that the " moral imperative " is the psychical correlate of cer- 
tain activities of the cerebro-spinal system (taken as the nem-al basis of 
the life of relation) as opposed to activities of the sympathetic system 
(taken as the neural basis of the vegetative and emotional Ufe). 

Philosophy and Criticism. 

KiEKPATEiCK : Observations on College Seniors and Electives in 
Psychological Subjects. Ihid., Vol. 3, pp. 168-173 (1890). 

A study of questionnaire returns from college seniors as to their rear 

sons for studying philosophical and psychological subjects, benefit gained, 
authors most impressive, and special topics found most interesting. 

Hall : Contemporary Psychologists. I., Prof. Eduard Zeller. Ihid., 
Vol. 4, pp. 156-175 (1891). 

An account of the life and writings of Zeller. 

Fkaser : Visualization as a Chief Source of the Psychology of 
Hobbes, Locke, Berkeley, and Hume. Ihid., Vol. 4, pp. 230-247 
(1891). 

The Psychological Foundation of Natural Realism. Ihid., Yol. 
4, pp. 429-450 (1892). 



136 Department of 

The Psychological Basis of Hegelism. Ibid., Vol. 5, pp. 472- 
495 (1893). 

These papers are the result of an effort toward a "psychology of phi- 
losophy." The first two trace the influence of concepts derived from 
vision and from touch on the philosophic schools in question, and the 
third the influence of those derived from galvanism. 

Bailey : Ejective Philosophy. lUd., Vol. 5, pp. 465-471 (1893). 

An attempt to describe briefly the philosophical "signs of the 
times." 

Letjba : National Destruction and Construction in France as seen in 
Modern Literature and in the Neo-Christian Movement. Ibid., 
Vol. 5, pp. 496-539 (1893). 

A review of these topics under the following heads : Artist sensual- 
ists, The quest for new sensations, Nihilism and pessimism. School of the 
decadents. Literary critics. Chronicles, The tormented. The Neo-Chris- 
tian movement. 

Allin : The " Recognition-theory " of Perception. Ibid., Vol. 7, pp. 
237-248 (1896). 

Recognition. Ibid., Vol. 7, pp. 249-273 (1896). 

The first paper is a critique of a theory of perception widely held in 
the past and present ; the second is an analytical, critical, and expository 
account of the mental experience of recognition. 

Mental and Physical Peculiarities. 

Scripture : Arithmetical Prodigies. Ibid., Vol. 4, pp. 1-59 (1891). 

Accounts of a large mmiber of phenomenal calculators collected from 
widely scattered sources ; analysis and discussion of their mental pecu- 
liarities, and pedagogical inferences. 

Krohn : Pseudo-chromsesthesia, or the Association of Colors with 
Words, Letters, and Sounds. Ibid., Vol. 5, pp. 20-41 (1892). 

A summary of literature with presentation of several new cases, and a 
discussion of the theory of the phenomenon, followed by a bibliography. 

LiNDLEY : A Preliminary Study of some of the Motor Phenomena of 
Mental Effort. Ibid., Vol. 7, pp. 491-517 (1896). 

A study, on the basis of a questionnaire and special tests, of the tricks 
and peculiarities of movement and posture that accompany mental effort. 



Psychology. 137 

LiNDLEY AND PARTRIDGE : Some Mental Automatisms. Pedagogical 
Seminary, Vol. 5, pp. 41-60 (1897). 

A questionnaire study of 495 cases of such mental automatisms as the 
avoidance of stepping on cracks, counting objects unnecessarily, group- 
ing objects like small patterns in wall paper into regular figures, and 
the picking out the middle one of rows of objects. 

Phillips : Genesis of Number Forms. Am. Jour, of Psy., Vol. 8, 
pp. 506-527 (1897). 

A study, based on over 2000 cases (974 school children, and nearly 
700 normal school pupils and adults personally questioned), showing the 
almost universal presence of number forms, though often in very rudi- 
mentary condition. 

COLEGROVE : Individual Memories. Ibid., Vol. 10, pp. 228-255 (1899). 
(Dissertation.) 

The paper is a study of some sixteen hundred replies to a question- 
naire on earliest memories, period of life best remembered, forgetful- 
ness and false memories, aids to memory, etc. This paper is an extract 
from a more extended work on memory in general. 



Emotion. 



Hall : A Study of Fears. Ibid., Vol. 8, pp. 147-249 (1897). 

Discussion of the chief fears of seventeen hundred people mostly 
under twenty-three years of age, together with description of methods 
used in reducing the original reports for general treatment. Fears of 
high places and falling, of losing orientation, of being shut in, of water, 
of wind, of celestial objects, of fire, of darkness ; di-eam fears ; shock ; 
fears of thunder, of animals, of eyes, of teeth, of fur, of feathers; 
special fears of persons, of solitude, of death, of diseases ; moral and 
religious fears ; fear of the end of the world, of ghosts ; morbid fears ; 
school fears ; and the repression of fears, — are all treated in separate 
sections. 

Hall and Allin: The Psychology of Tickling, Laughing, and the 
Comic. Ibid., Vol. 9, pp. 1-41 (1897). 

A study based upon about seven hundred questionnaire returns. The 
following rubrics are treated: The Physical act of laughing. Tickling, 
Animals and their acts. Recovery from slight fear. Laughter at calamity. 
Practical jokes, Caricature, Wit, Laughter at what is forbidden or secret, 
at the naive and unconscious. Animal laughter, Miscellaneous items, and 
Notes on literature. 



138 Department of 

Hall : A Study of Anger. Ibid., Vol. 10, pp. 516-591 (1899). 

A general summary of very widely gathered literary material, followed 
by a discussion of over two thousand questionnaire returns ; General 
descriptions of the state, Causes (with many sub-heads), Subjective 
variations, Physical manifestations (with many sub-heads), Anger at 
inanimate and insentient objects. Venting anger, Eeaction, Control, 
Treatment, Miscellaneous aspects. 

Miscellaneous Topics. 

MacDonald : Ethics as Applied to Criminology. Journal of Mental 
Science, Vol. 37, pp. 10-16 (1891). 

Criminal Aristocracy, or the Maffia. Medico-Legal Journal, 
Vol. 9, pp. 21-26 (1891). 
Le Rossignol : The Training of Animals. Am. Jour, of Psy., Vol. 
5, pp. 205-213 (1892). 

A review of literature on the subject. 

Keohn : Facilities in Experimental Psychology at Various German 
Universities. Ibid., Vol. 4, pp. 585-594 (1892); Vol. 5, pp. 282- 
284 (1892). 

Notes on Heidelberg, Strasburg, Zurich, Freiburg, Munich, Prag, Ber- 
lin, Leipzig, Halle, Jena, Bonn, and Gottingen. 

Lemon: Psychic Effects of the Weather. Ibid., Vol. 6, pp. 277-279 
(1894). 

A preliminary note on the general question. 

Scott : Sex and Art. Ibid., Vol. 7, pp. 153-226 (1896). 

The study traces the higher enthusiasms of art and religion, as well as 
the passions of sex, to the " fundamental quality of erethism found in 
every animal cell." Beginning with erethism, the following topics are 
discussed: Specialization among cells, Separation of the sexes, Eadiar 
tion. Selection, Combat, Courting, Fear and anger. Sex and care for 
young. The aesthetic capacity, Courting instinct in the lower races, 
Tattooing, Clothing, Shame, Jealousy and fear, Symbolism and fetich- 
ism, Phallicism, Modern phallicism. General features and laws of court- 
ing, Degeneration, Perversion, Ecstasy, jEsthetics, Conclusion. 

ScOTT : Old Age and Death. Ibid., Vol. 8, pp. 67-122 (1896). (Dis- 
sertation.) 

Old age and death treated from biological and physiological stand- 
points, together with discussion of 226 returns to a questionnaire designed 



Psychology. 139 

to bring out the ideas of young people and others with regard to the 
aged, to death, and to a future life. 

Partridge : Blushing. Pedagogical Seminary, Vol. 4, pp. 387-394 
(1897). 

A questionnaire study (120 cases, all normal school pupils) : Objective 
and subjective aspects, After-effects, Physiology, Psychology, Blushing 
and sex. 

Partridge: Second Breath. Ibid., Vol. 4, pp. 372-381 (1897). 

A study based upon about two hundred questionnaire returns. The 
following are the headings : Physical second breath, Mental second 
breath, Over-play and abandon in children, Eeaction, Physiology of 
second breath. 

LiNDLEY: A Study of Puzzles with Special Reference to the Psy- 
chology of Mental Adaptation. Am. Jour, of Psy., Vol. 8, pp. 
431-493 (1897). (Dissertation.) 

The subject is introduced by a consideration of the biology and psy- 
chology of play in general, followed by the classification of puzzles. 
The time and conditions of greatest interest in puzzles are treated on the 
basis of questionnaire returns. This is followed by a rej)ort of extended 
experiments made upon school children to discover their growth in abil- 
ity to deal with the difficulties presented by puzzles. 

Kline: The Migratory Impulse vs. Love of Home. Ibid., Vol. 10, 
pp. 1-81 (1898). (Dissertation.) 

A biological and psychological study combining the results of experi- 
ments upon animals with those of a questionnaire. Such topics as the 
Influence of temperature, Spring fever, Migrations of wild and domestic 
animals and of man. Wandering tendency in men, women, and childi-en. 
Love of home, and homesickness, are treated. 

QuANTZ : Dendro-psychoses. Ibid., Vol. 9, pp. 449-506 (1898). 

A study on material gathered from biology, anthropology, and ques- 
tionnaire returns of the psychic influence of experiences -with trees. 
Biological evidence of man's descent from arboreal ancestors, Psychical 
reverberations from ancestral experience, Tree worship, The life tree. 
The tree in folk-medicine. The tree in child life. The tree in poetry. 

Bolton, F. E. : Hydro-psychoses. Ibid., Vol. 10, pp. 171-227 
(1899). (Dissertation.) 

A study, similar to the last, on the psychic effects of experiences with 
water : Evidences of man's pelagic ancestry. Origin of animal life, Ani- 



140 Department of 

mal retrogression to aquatic life, Water in primitive conceptions of life, 
in philosophical speculation, Sacred waters, Water deities, Lustrations 
and ceremonial purifications by water, Water in literature, Feelings of 
people at present toward water. 

GoDDAED : The Effects of Mind on Body as evidenced by Faith 
Cures. Ihid., Vol. 10, pp. 431-502 (1899). (Dissertation.) 

"Christian Science," "Divine Healing," hypnotism and other forms 
of mental treatment of disease are briefly considered ; and " Mental Sci- 
ence," taken as a type, is treated fully from data gathered by extended 
correspondence and from hospital records. In the remainder of the 
paper the following topics appear : Positive testimony of the influence 
of mind on disease. Failures in the practice of mental therapeutics, 
Hypnotism as a therapeutic agent. Theory of mental therapeutics. Psy- 
chological problems suggested, Eesume and conclusions. 

Street : A Genetic Study of Immortality. Pedagogical Seminary, 
Vol. 6, pp. 267-313 (1899). (Dissertation.) 

A study of the origin and characteristics of ideas of the soul, im- 
mortality, heaven, and a future life, made on the basis of the reports 
of the thoughts of deaf mutes before training, on about five hundred 
replies to a questionnaire, and on other material. Biological, psychologi- 
cal, and moral aspects of the belief in immortality are also considered. 

Besides the studies of these lists, which have been printed, a number 
more have been made and are in the hands of the instructors practically 
ready for publication. Others still have been made and the data sub- 
mitted without complete writing out ; a good part of these will ultimately 
be made use of either in themselves or as the basis for further research 
along the same lines. 



After this outline of work done in the past, a few words may be per- 
mitted with reference to the future of the department. This, like its 
past, must be closely connected with the general progress of psychological 
science, and the question naturally becomes that of the directions in which 
progress may be most reasonably expected. Let me begin, as before, with 
the laboratory. 

It seems to me that the two lines of greatest promise, conceding readily 



Psychology. 141 

the importance of continuing research along lines already undertaken, are 
those of comparative and of individual psychology. Work has already 
been begun in both fields. Especially in comparative psychology much 
has already been done by the biologists, but much remains yet to be done. 
There is surprisingly little accurate knowledge of the mental life of even 
the commonest animals ; there are many anecdotes, but not many reliable 
observations, and very few experiments. In this field lie the questions of 
instinct and heredity, belonging alike to psychology and biology, to which 
run back so many of the most fundamental and practical of even strictly 
psychological questions. Much may also be expected from the full intro- 
duction into psychology of the comparative method which has so broad- 
ened and enriched other sciences in which it has been applied. The 
conception of mind, as of something not narrowly human or confined to a 
few higher animals, but as in some sort present in all animals, even the 
lowest, with a history as long as evolution, opens up vistas to which psy-. 
chologists have been too little accustomed. Much surely is to be expected 
from this closer alliance of psychology with biology. 

While the theoretical interest of comparative psychology is thus 
hardly to be overestimated, the practical interest of the efforts toward an 
individual psychology is hardly less important. We know something 
about the mental differences of our fellow-men, but we know very little 
about them in a scientific way. What underlies temperament? What 
are the laws of the growth of character? Why do some pupils do well 
with some teachers and not with others ? What is the best treatment for 
reform school boys ? How shall one deal with exceptional and peculiar 
children in the family? Individual psychology ought to answer such 
questions as these, and many others. It is clear, of course, that many of 
these questions extend far beyond the possibilities of the laboratory, but 
the methods and standpoint and training of the laboratory wiU play no 
small part in their final solution, and justify attacking them from that 
side. 

Closely connected with individual psychology, but lying a little fur- 
ther from the laboratory, is another field which might be called the 
" psychology of the permanent apperceptive groups " — the study of the 
mental attitudes, that is, that result from the fundamental experiences of 
life, a study of apperception which does not stop at demonstrating the 
fact of mental habit, but goes on to investigate the effect of one sort of 
mental habit upon the rest ; how, for example, the fact of fatherhood or 



142 Department of 

a severe sickness may alter character distinctly and permanently. These 
topics have not been neglected, but many questions remain that ■would 
well repay the worker of proper equipment and insight. Coordinate with 
these are the study of the more complex emotions, of religion and of 
aesthetics, all of which promise much and should have an important place 
in a psychological department as a counterweight to the laboratory. It 
is on the data obtained from the study of these topics and those of the 
last group, with others like them, that true mental and moral hygiene 
must rest. Fortunately, here also we have beginnings. 

Beyond these again, there are topics of great popular interest, like 
those of Christian science and psychical research, upon which the lay- 
man has a right to ask an expert opinion from science, and on which 
psychology, after careful investigation, can and ought to speak. 

What any particular department of psychology can do in realizing 
these promises of the future, must depend upon the resources in men and 
materials that it can command. Work in comparative psychology can be 
begun at once wherever suitable accommodations can be provided for the 
animals, — proper housing, cages, aquaria, and such attendance as shall 
insure the health and happiness of the animals, which are essential factors 
in any reliable study of their behavior, — and a properly qualified observer 
can be secured. The first of these requirements is easier to fill at present 
than the second, for as yet too few persons have equipped themselves both 
as psychologists and naturalists, but this lack will not long exist if the 
subject is taken up in earnest. For the portion of individual psychology 
that comes within the scope of the laboratory, there is need of new instru- 
ments of at least a relative precision, many of which must yet be devised 
or slowly perfected by trial and failure, which involves a liberal subsidy. 
For any of the more general problems mentioned, the first requisite is 
men of proper natural equipment and training. Not every man of learn- 
ing is fitted to handle them, and those devoted to them must not be so 
much taken up with the routine and responsibility of elementary teaching, 
that they lack the time and spirit for ardent research. And these men, 
once secured, must be liberally supplied with such help in the way of 
books and other materials as they need. Of these three things, — quarters 
for comparative psychology, apparatus for individual psychology, and an 
enlargement of the staff, — the last is, in all ways, by far the most impor- 
tant. Competent and enthusiastic investigators can work with inadequate 
facilities, but no facilities can take the place of the men or of the freedom 



Psychology. 143 

from routine teaching. The Clark department has already made such 
efforts in all these lines as its opportunities have permitted. Its ten years' 
history justifies the prophecy that, with enlarged opportunities, it would 
make more than commensurate return in an increase of the advanced 
teaching and research for which it was originally organized. 



PSYCHO-PATHOLOGY. 

By Adolf Meyek. 

It is hardly necessary to insist to-day on the remarkably suggestive 
influence which pathology has had on the biology of man, and especially 
on psychology. Many of the most fundamental changes in psychology 
are directly traceable to problems furnished by the study of abnormal 
life, clinical and post-mortem pathology, and experimental reproduction 
of diseases and of symptom-complexes. Under these conditions it is 
evident that the curriculum of a psychologist, and of biologists generally, 
is quite incomplete without, at least, some touch with results and problems 
of general pathology, and more especially of neuro- and psycho-pathology. 

Starting from the experience that certain types of psycho-pathology 
lead very promptly into paths which have nothing to do with biology, 
and put themselves directly on pre-biological traditions, it was considered 
best to develop a course which would begin with the principles of general 
pathology, the abnormalities of the most general biological factors, i.e. 
with a chapter properly belonging to any general biology. In this 
field, the experience in the domain of neurology and of psychiatry 
would have to be worked up more carefully, as far as possible in constant 
touch with the broader biological concepts. 

Medicine, barely deserving the attribute of an applied science, is 
not rich in literature breathing the biological spirit. To a great extent 
it stands on a pre-biological, materialistic standpoint, and the orthodox 
practitioner of medicine is usually anxious to keep to materialism and 
to profess ignorance of the psychological aspect ; and, again, many of 
those who look upon the psychological manifestations in their patients 
very rapidly acquire one of the traditional exclusive standpoints, danger- 
ously near certain mystical concepts. The psychology of hypnotism, 
of hysteria, even that of aphasia, give good instances of such tendencies. 
It is consequently desirable to build up a course from the elementary 
to the more difficult, and starting from the least contested foundations 
to proceed to the less comprehensible points. 

144 



Psyclio-Pathology. 145 

The plan outlined in the lectures and clinics of the spring of 1897 
gives an idea of the work. 

The course during the year covered the following ground : — 

1. Introductory remarks on general biological conceptions. The gen- 
eral biological principles applied to the study of abnormal life. Relation 
between neurology and psychology, neuro-pathology and psychiatry, neuro- 
logical and psychical phenomena from the biological standpoint. Appli- 
cation of the point of view to alcoholic intoxication and to several forms 
of mental disease. Demonstration : Cases of Febrile Delirium, General 
Paralysis, Catatonia, and Idiocy. 

2. Review of the general pathology on the ground of the aspect- 
hypothesis. The terms " disease," " residual," " defective formation," and 
" defective Anlage." Clinical and post-mortem pathology and their share 
in general pathology. Only clinical pathology furnishes data on the psy- 
chological and physiological side. Plan of clinical study. Anatomical 
study. Our knowledge of the macroscopic and microscopic lesions 
of the nervous system and the underlying pathological processes, 
defective growth and nutrition, intoxication, abnormal function. Local 
disorders : Abnormal circulation, local intoxications, traumatic disorders, 
over activity, perverted function. Demonstration of abnormal brains and 
histological changes. 

3. The general plan of the nervous system and illustrations of 
diseases of the various parts (levels). The neural tube; the segmentary 
arrangement and the elements of the segments within the lowest level. 
The middle level apparatus — cerebellum, midbrain, and forebrain, and 
their afferent and efferent connections. Demonstrations : (1) Traumatic 
paralysis of the nervus peroneus. (2) Infantile paralysis. (3) Cases of 
hemiplegia. (4) Lead paralysis (Remak type). (5) Alcoholneuritis. 
(6) Locomotor ataxia. 

4. The principles of localization. The meaning of the connections 
of neurones by numerous collaterals, of the " interruptions of the tracts 
by gray matter," of the term "centre." Description of the most 
important "centres," the lesions of the apparatus of mimic movements, 
the sensorimotor areas, the principal "sensory" projection fields. An 
outline of the principles of aphasia and its forms, of hemianopsia. 
Highest level symptoms. Demonstration : Hemiplegia with hemianop- 
sia ; two cases of hemiplegia with motor aphasia ; one case of sensory 
aphasia. Reference to a case of Brown-Sequard paralysis. 



146 Psycho-Pathology. 

5. General outline of mental diseases. Explanation of Kraepelin's 
classification. Illustration of a paradigm of mental disease : General 
Paralysis, its etiology, symptomatology, and principal types. Demonstra- 
tion of six cases. 

6. Toxic psychoses and psychoses of disturbed metabolism. Sum- 
mary of the data of psycho-physiological study of fatigue and intoxication 
furnished by the school of Kraepelin. Review of the methods and the 
results. Application to the clinical problems. Demonstration : Delirium 
Tremens, Subacute Alcoholic Insanity. Cretinism. Dementia Precox and 
Catatonia. 

7. Periodic Insanity compared with the types of Verbloedungs- 
processe. Demonstration of further types of Catatonia and of Periodic 
Insanity; "Acute Mania," "Acute Melancholia." 

8. Short sketch of Senile Dementia and demonstration of a case. 
Constitutional psychoses. Resume of the methods and aims of individual 
psychology (Cattell, Miinsterberg, Jastrow, Kraepelin, Gilbert, Binet et 
Henri, Guicciardi and Ferrari). Value of "types" of character or 
constitution. Their formation. Dominant ideas. Mysophobia as a 
type of Neurosis of Fear. Development of Paranoia ; cases of Paranoia. 

In the spring of 1896 a similar course of demonstrations had been 
given (see the outline, American Journal of Psychology, April, 1896, 
Vol. 7, pp. 449-450). In the spring of 1898 only one lecture was possible 
(on the methods of individual psychology, especially Kraepelin's work) 
and a short course of four clinics in the spring of 1899. The desire to 
extend the studies into research work has remained unfulfilled. Several 
attempts failed because the possibilities for such work were not mature, 
neither on the side of the hospital nor on the part of the University. 

The general principles of the work at Clark University tend toward 
the education of workers. So far the sub-department of psycho-pathology 
has been purely didactic, covered by the lectures of President Hall, on 
the topics which have specially attracted psychology, e.g., border-line 
phenomena, as seen in neurotic people, prodigies, and geniuses; defec- 
tives, such as the blind, deaf, criminal, idiotic ; mental and nervous 
diseases, epilepsy, phobias, neurasthenia, hysteria ; morbid modifications 
of will, personality, emotion, etc., and by the above attempt at giving a 
course with clinics based on general pathology. 

The research work along these lines depends on two important condi- 
tions. For systematic work the organization of a clinic is necessary, 



Psyclio-Pathology. 147 

and on the part of the worker a fair knowledge of general and special 
pathology (in its broadest sense — the knowledge of abnormal life, not 
merely pathological anatomy and bacteriology) is an absolute pre- 
requisite. 

A training in general and special pathology on the ground of a 
complete course of biology must be regarded as an absolutely necessary 
pre-requisite for research in psycho-pathology. Whether most courses 
of medicine offer what is needed, and whether a medical education 
should be required, is a matter of some doubt ; since much of the ordinary 
medical course is business training rather than work in pathology in 
the true sense of the word, leaving out almost intentionally the broader 
aspects which we have to require more especially for research in our 
lines ; and most of the medical courses are so overburdened that the 
training in the history of human thought and philosophical criticism 
is completely crowded out, and this important safety-valve and balancing 
apparatus is almost missing in the medical curriculum. 

The other point, the creation of clinical possibilities, is not less 
difficult. Our attempt at the Worcester Insane Hospital has hardly 
matured sufficiently to allow of much research work. The work which 
forms the foundation of research must be done first, and the reorganiza- 
tion begun in 1896 is only just beginning to furnish the material for 
some studies suggested by Dr. Sanford, and some investigations on 
more closely psychiatric questions. 

The study of the most protracted disorders of human life requires 
such a patient spirit of work and an atmosphere of such tenacious 
adherence to solid working principles, that the predilection for fads 
and the haste for results are nowhere more lamentable. Should it be 
the good fortune of this department to get strengthened by the State, 
as well as by the University, a psychiatric clinic and research-station 
might grow up. Efforts of this character are being made in New York 
by an institute independent of the hospitals. Our plan is rather to develop 
the research-station on the basis of the clinical work. The constant con- 
tact with a field of experience such as a clinic offers furnishes the safest 
working basis and prevents one from running away with hasty specula- 
tion derived from too limited a number of facts. The best field for 
getting problems for work is that of actual observation, such as a clinic 
only can afford. To pick out curiosities merely will never lead to a 
psycho-pathology worth its name. 



ANTHROPOLOGY. 

By Alexander Francis Chamberlain. 

The history of the Department of Anthropology at Clark University 
forms an important chapter in the history of the study of anthropology in 
America, since it was the first educational institution to distinctly recog- 
nize anthropology as a subject of graduate study leading to the degree of 
Doctor of Philosophy. 

The first official announcement of the University, published in May, 
1889, included, under the work to be undertaken in the Department of 
Psychology, the following subjects : " The Psychology of Language ; 
Myth, Custom, and Belief anthropologically considered." With the 
opening of the academic year, anthropology was established as Section 
C of the Department of Psychology, and a laboratory and departmental 
library provided, with proper facilities for original investigation and 
research. The laboratory contained crania for practical study, necessary 
craniographic and craniometric instruments, together with the usual tools 
of the anthropologist working in the field. 

The library of the University, besides a special anthropological collec- 
tion, contains a very complete selection of the literature on applied ethics 
(criminology), embracing the chief works of the English, Italian, French, 
and German writers. In the psychological library will be found also 
many works relating to the subjects which anthropology and psychology 
treat of in common. 

In 1889 Dr. Franz Boas (now Professor of Anthropology at Columbia 
University, New York), a graduate of the University of Kiel, who was 
already well known through his researches among the Eskimo of Baffin 
Land and the Indians of Alaska and British Columbia, was appointed 
Docent in Anthropology, which position he held until the close of the 
academic year, 1891-92, when he assumed the duties of director of the 
sub-department of physical anthropology at the World's Columbian 
Exposition, taking with him his fine collection of crania. At the Uni- 

148 



Anthropology. 149 

versity Dr. Boas continued his studies of the anthropology of the 
Northwest Coast, paying especial attention to a monograph on " The 
Mythologies of the North Pacific Coast," which he prepared for pub- 
lication, and to osteological studies of the material collected during his 
several journeys. 

In the summer of 1890 Dr. Boas was engaged in investigating the 
anthropology, ethnology, and linguistics of the Indian tribes of the coast 
of British Columbia, under the auspices of the British Association for 
the Advancement of Science. His report, presented to the Leeds meeting 
in 1891, treated of the customs and beliefs of the Bella Coola, who were 
shown to be of Salishan stock, besides containing a general review of the 
physical characteristics of the Indians of the North Pacific coast, with a 
discussion of the problem of mixed races. Studies of the Chemakum and 
Chinook languages were also continued and articles prepared for publica- 
tion. Early in 1890, the approval of the school authorities having been 
obtained, an extensive series of anthropological measurements was begun 
in the schools of the city of Worcester, and carried to successful comple- 
tion. Preparations were also made for the inauguration of similar 
investigations in other parts of the Union and in Canada. These 
measurements were undertaken with the object of studying the growth 
of children as influenced by varying conditions. The investigations in 
Worcester were carried on by Dr. Boas, with the assistance of the follow- 
ing members of the University : Dr. G. M. West, Mr. A. F. Chamberlain, 
Mr. T. L. Bolton, Mr. J. F. Reigart. In the spring of 1891 preparations 
were made for extensive anthropological measurements of the American 
Indians, under the auspices of the World's Columbian Exposition, Dr. 
Boas being placed in charge of the sub-department of physical anthro- 
pology. In prosecution of these investigations, the following students of 
the University, trained in the anthropological laboratory, were engaged 
during the summer : Dr. G. M. West, in Quebec and the maritime 
provinces of Canada; Mr. T. F. Holgate, in eastern Ontario; Dr. T. 
Proctor Hall, in western Ontario ; Mr. T. L. Bolton, in Idaho and Utah. 
Other observers "were similarly employed in Alaska, British Columbia, 
the northwest territories of Canada, Labrador, Dakota, Wisconsin, 
Washington, Oregon, New Mexico, Yucatan, etc. The chief object of 
the extensive investigation thus begun is to show the distribution of 
types over the American continent, and to settle, if possible, disputed 
points regarding the physical anthropology of the Indians. In the 



150 Anthropology. 

summer of 1891 Dr. Boas resumed his investigations of the Indians of 
British Columbia for the British Association, and also visited the last 
survivor of the Chinook tribe, from whom he obtained very valuable 
ethnologic and linguistic data. 

During the academic years, 1889-92, Dr. Walter Channing, of Brook- 
line, Mass., Honorary Fellow of the University, carried on original investi- 
gations in the laboratory of the department. 

In November, 1890, Dr. G. M. West (afterward Instructor in 
Anthropology in the University of Chicago), a graduate of Columbia 
College, was appointed Fellow (and afterward Assistant) in Anthro- 
pology, and devoted himself to the consideration of its physical side, 
taking a large part in the anthropometric investigations begun in the 
Worcester schools. During the summer of 1891 Dr. West was engaged 
in anthropological measurements of the Indian tribes of Quebec and the 
maritime provinces of Canada. Appointed Assistant in Anthropology in 
1891, he continued in that position until the close of the academic year 
1891-92, when he became associated with Dr. Boas in the sub-depart- 
ment of anthropology in the World's Columbian Exposition, having 
charge of the anthropological investigations during Dr. Boas's absence in 
Europe. 

During the Docentship of Dr. Boas the lectures of the department 
were as follows : — 

1. A course of lectures on : Physical Anthropology, Osteology, and 
particularly Craniology. The Physical Character of the living subject : 
Anatomy of Races. In connection with these lectures practical work was 
carried on in the laboratory. 

2. A course of lectures on : The Anthropology of Africa, embracing 
the consideration of the geographical distribution, physical characters, 
languages, and culture of the native tribes. 

3. A course of lectures on: The Application of Statistics to Anthro- 
pology. 

In the spring of 1892 Dr. West delivered a course of lectures on 
The Growth of School Children, based upon the results obtained in the 
Worcester schools. These lectures have been published in Science and 
the Archiv fur Anthropologie. 

In the spring of 1890 Mr. A. F. Chamberlain, a graduate of the 
University of Toronto, then Fellow in Modern Languages in University 
College, Toronto, who had been a student in ethnology under the late Sir 



Anthropology. 151 

Daniel Wilson, was appointed to the first fellowship created in anthro- 
pology in the University. Previous to entering upon the course of study 
for the doctorate, Mr. Chamberlain had made special investigations of 
the Algonkian Indian languages, and these he contiuued, offering as his 
thesis an original monograph, "The Language of the Mississagas of 
Skugog," which was published in 1892. Other briefer essays in the 
same field have appeared in the Proceedings of the Canadian Institute 
(Toronto), Canadian Indian, American Anthropologist, Journal of Ameri- 
can Folk-Lore, Proceedings of the American Association for the Advancement 
of Science, etc., dui'ing the years 1888-99. 

Time snatched from busy hours from 1891 to 1893 was devoted to 
original investigations in the language and folk-lore of the Canadian 
French, some results of which have been published in Modern Language 
Notes (Baltimore), Vols. 6-8. In 1892 was published the result of an 
extensive investigation of the use of " Diminutives in -ing," in the Platt- 
Deutsch (Low German) dialects, another study from which field, " Color 
Comparisons in the Low German Dialects," subsequently appeared. 

In the spring of 1891 Dr. Chamberlain delivered a brief course of 
lectures on " The Relationship of Linguistics to Psychology and Anthro- 
pology." In the fall of the same year he assisted in the anthropometric 
investigations carried on in the schools of the city of Worcester under 
the direction of Dr. Boas, and in April-May, 1892, superintended the 
measurements of some 15,000 school children in Toronto, Canada, the 
results of which work are being from time to time published (see Report 
of Commissioner of Education, 1896-97, Vol. 2) by Dr. Boas, under whose 
auspices it was carried out. 

From June to October, 1891, he was absent among the Kootenay 
Indians of southeastern British Columbia and Northern Idaho, having 
been selected by the committee of the British Association for the Ad- 
vancement of Science to carry on anthropological investigations among 
the Indian tribes of northwestern Canada. His report (discussing in 
detail the ethnography, physical anthropology, mythology, and language 
of this comparatively unknown aboriginal people) was presented at the 
Edinburgh (1892) meeting of the Association and printed, with an 
introduction by Horatio Hale, as the " Eighth Report on the Northwestern 
Tribes of Canada" (London, 1892, 71 pp.). Other briefer studies, 
botanical, linguistic, mythological, psychological, based upon the material 
gathered during this expedition, have been published in the American 



152 Anthropology. 

Anthropologist, American Antiquarian, Journal of American Folk-Lore, 
Verliandlungen der Berliner anthropologischen Cresellschqft, Archivio per 
VAntr apologia, Am Ur- Quell, Science, etc. The great mass of material, 
however, is still in process of preparation for publication, and will, when 
complete, make some four good-sized treatises or volumes as follows : — 

1. Kootenay Indian Art. An Interpretative and Comparative Study of some 
Three Hundred Drawings of Natural Objects, Hiiman Beings, Animals, etc., 
made by various Indians of the Upper and Lower Kootenay. 

2. Mythology of the Kootenay Indians. A Comparative and Interpretative Study 

of some Fifty Animal Tales and Legends of the Kootenay Indians. With 
original Indian Text, Translation, Explanatory Notes, etc. 
3^. Dictionary of the Kootenay Language, with Introduction on Grammar and 
Morphology. Part I., Kootenay-English ; Part II., English-Kootenay. 

As much time as could reasonably be spared from other duties has 
been devoted to the long and difficult task of compilation and revision of 
these original studies. 

During his tenure of the Lectureship in Anthropology, Dr. Chamber- 
lain has lectured twice a week throughout the academic year, the following 
courses having been delivered: — 

1892-93. Mythology of the North American Indians. 

The syllabus and bibliography of this detailed interpretative study have 
been published in the " Third Annual Report of the President to the Trustees 
of Clark University," 1893, pp. 123-125, 141-161. Several of the lectures have 
appeared in full, or in abstract, in the Jotirual of American Folk-Lore. 

1893-94. General Course : The Science of Anthropology in its Relations to 
Psychology and Pedagogy. Special Courses : (o) Comparative Mythology 
of Ancient Greece and Italy ; (&) Child Life among Primitive Eaces, the 
American Indians especially. 

The introductory lecture of this course, under the title "Anthropology in 
Universities and Colleges," with brief historical bibliography, has been pub- 
lished in part in the Pedagogical Seminary, Vol. 3, pp. 48-60. An abstract of 
one of the lectures in course (6) has appeared as "Notes on Indian Child 
Language," in the American Anthropologist, Vol. 3, pp. 237-241 ; Vol. 6, pp. 
321-322. 

1894-96. Besides the course in General Anthropology, the following brief 
special courses were delivered : Anthropology and Ethnology of Sex ; The 
Child amongst Primitive Peoples ; Comparative Mythology of America and 



Anthropology. 153 

the Old World; Psychology of Primitive Languages; The Beginnings of 
Art and Language; The ^sthetical Ideas of Primitive Peoples. 

The lectures on the "Psychology of Primitive Languages" were based upon 
original investigations among the Algonkian Indians of Canada, and the Koote- 
nay Indians of British Columbia, and abstracts of several of them have been 
published in the American Anthroxiologist, Vol. 7 (1894), pp. 68-69, 186-192 ; 
Verhandlungen der Berliner anthropologischen Gesellschaft, 1893, pp. 421-425, 
1895, pp. 551-556 ; ArcMvio per I' Antropologia e la Etnologia (Firenze), Vol. 
23 (1893), pp. 393-399. 

The lectures on "The Child among Primitive Peoples," delivered also in 
popular form at the Summer School in July, 1894, have been elaborated and 
published as a book, with the title " The Child and Childhood in Folk-Thought " 
(New York, Macmillan, 1896). 

1895-96. Besides the course in General Anthropology, the following special 
and briefer courses were delivered: Anthropometry of Children and Youth; 
The Emotions and their Expression among Primitive Kaces ; The Idea of 
the Soul among Primitive Peoples ; Crime and Degeneracy among the Lower 
Eaces of Man; Origin and Development of the Family; Sociological History 
of Woman. 

Two of the lectures on " The Emotions and their Expression among Primi- 
tive Peoples " have appeared in part in the American Journal of Psychology, 
Vol. 10, pp. 301-305, "Fear," and Vol. 6, pp. 685-592, "Anger." 

1896-97. Besides the course in General Anthropology, the following briefer 
special courses were delivered : The Philosophy of Primitive Mythologies ; 
Origin and Development of Social Institutions ; Eace-Psychology ; The 
Anthropology of Childhood ; Civilization and Evolution. 

One of the lectures in the course on "The Philosophy of Primitive My- 
thology" appears, under the title "Folk-Lore and Mythology of Invention," in 
the Journal of American Folk-Lore, Vol. 10 (1897), pp. 89-100. 

1897-98. Besides the course in General Anthropology, the following briefer 
special courses were delivered : The Anthropology of Sex ; Primitive Children 
and Children of Civilized Races ; Social Evolution ; Origin and Development 
of Primitive Religions ; Anthropometry. 

1898-99. Besides the course in General Anthropology, the following special 
briefer courses have been delivered : Child Study in Italy, Variation and 
Degeneration, Heredity and Environment. 

Outside of the academic and summer school courses the following 
lectures and addresses on topics of general interest have been delivered 
from time to time in Worcester and elsewhere : — 



154 Anthropology. 

1892. Aims and Methods of Anthropometry. Principals and Teachers of 
Grammar Schools, Toronto. 

1892. Optimism. Canadian Club, Clark University, Worcester. 

1893. Savage Views of Nature. Natural History Society, Worcester. 

1893. The American Indian. Men's Association, Pilgrim Church, Worcester, 

Mass. 

1894. Woman's Eole in the Development of Eeligion and Civilization. Fort- 

nightly Club, Woonsocket, E.I. 

1895. The World's Debt to the Eed Man. Natural History Society, Sterling, 

Mass. 

1895. The Mother and the Child in the Story of Eeligion and Civilization. 

South Unitarian Church, Worcester, Mass. 

1896. Childhood. Conference of Lend-a-Hand Clubs, Lowell, Mass. 
1896. The American Indian. Universalist Church, New Britain, Conn. 

1896. The Making of Abraham Lincoln. South Unitarian Church, Worcester, 

Mass. 

1897. Johanna Ambrosius. Lend-a-Hand Clubs, South Unitarian Church, 

Worcester, Mass. 
1897. Youth. Lend-a-Hand Conference, Boston, Mass. 
1897. Lincoln and Darwin. South Unitarian Church, Worcester, Mass. 
1897. In Memoriam : Henry George. South Unitarian Church, Worcester, Mass. 

1897. The Unitarian Church and Alcoholism. Conference of Unitarian 

Churches, Barre, Mass. 

1898. Primitive Nature Study. Jacob Tome Institute, Port Deposit, Md. 

1899. The Child and the Criminal. Monday Morning Club (Universalist Min- 

isters), Boston, Mass. 

At the meetings of various scientific societies, 1890-99, the following 
papers have been presented, those marked * having been published since 
their delivery: — 

1. American Polk-Lore Society : — 

1890. *Nanibozhu among the Otcipwe, etc. 

1892. *Physiognomy and Physical Characteristics in Folk-Lore and Folk- 
Speech. 

1892. Christ in Folk-Lore. 

1893. Mythology of the Columbian Discovery of America. 

1895. *PoeticaI Aspects of American Aboriginal Speech. 

1896. *Folk-Lore and Mythology of Invention. 

1898. *American Indian Names of White Men and Women. 

2. Modem Language Association of America : — 

1891. *The Use of Diminutives in -ing by some writers in Low German 

Dialects. 



Anthropology. 155 

3. American Association for the Advancement of Science : — 

1893. Primitive Woman as Poet. 

1894. *Translation into Primitive Languages. (Abstract.) 
1894. *Incorporation in the Kootenay Language. 

1894. *Primitive Anthropometry and its Folk-Lore. (Abstract.) 

1895. *Kootenay Indian Personal Names. 

*Word Formation in the Kootenay Language. 

4. British Association for the Advancement of Science : — 

1892. *Kootenay Indians. 

1897. *Kootenay Indian Drawings. (Abstract.) 

1897. *The Kootenays and their Salishan Neighbors. (Abstract.) 

5. Berliner Anthropologische Gesellsehaf t : — 

1893. *Wurzeln aus der Sprache der Kitonaqa-Indianer. 
1895. *Beitrag zur Pflanzenkunde der Naturvolker America's. 

6. International Congress of Anthropology (Chicago) : — 

1893. *The Coyote and the Owl. (Tales of the Kootenay Indians.) 

Dr. Chamberlain has been a Councillor of the American Folk-Lore 
Society (1894), Secretary of the Anthropological Section of the Ameri- 
can Association for the Advancement of Science (189-1), and one of the 
secretaries of the Anthropological Section of the British Association for 
the Advancement of Science (1897). 

Since 1894 anthropology has been represented on the programme of 
the Summer School of the University, and each year Dr. Chamberlain has 
delivered a course of twelve daily lectures upon anthropological questions 
and topics of more or less interest to the teacher and to the general public. 
These courses have been as follows : — 

1894. Anthropology of Childhood. (The Child Among Primitive Peoples.) 

1895. Pedagogical and Psychological Aspects of Anthropology. 

1896. Anthropology of Childhood. (New Series.) 

1897. Anthropological Aspects of Childhood. 

1898. The Beginnings of Education and Educational Institutions. — Primitive 

Pedagogy. 

1899. Educational Aspects of Human Evolution. 

At the various summer schools the following topics have also been 
popularly treated in evening lectures : — 

1896. (a) The Philosophy of Childhood with the Poets. 
(6) The Genius of ChUdhood. 



156 Anthropology. 

1897. (a) The Divinity of Childhood. 

(h) The Attitude of Primitive Peoples toward Nature. 

1898. The Childhood of Genius. 

1899. (a) The Prophecy of Childhood. 

(&) The Making of a Genius. (Abraham Lincoln.) 

Anthropology, while comparatively a new, is by no means an uncom- 
mon, subject of academic instruction, and the time has distinctly passed 
when it should be called upon to plead for its existence, or to make an 
oratio pro domo. 

Very many of the great European universities have specifically rec- 
ognized anthropology as worthy of the highest positions in their gift, 
and, in this country, institutions like Harvard, Columbia, Chicago, and 
the University of Pennsylvania have endued this department with the 
full dignity of a professorship. Moreover, nearly twenty other colleges 
and imiversities in America now offer instruction in anthropology, as 
such, while Sociology, one of the most important branches of the science, 
is to be found on the curriculum of all such institutions as are making 
any efforts whatsoever to keep abreast of the times. Other branches of 
anthropology, such as Comparative Philology, Comparative Religion, 
Race Psychology, Anthropometry, Archaeology, Culture-History, etc., are 
finding more and more acceptance witli the higher institutions of learning. 

Both with respect to original research and to academic lectures, the 
representatives of anthropology in American universities have no reason 
to fear comparison with the professors and instructors in any other branch 
of science, and their influence in broadening and humanizing some of 
the more belated and conservative of the kindred branches of human 
knowledge can hardly be overestimated. 

It is a significant fact that the latest and most complete academic 
recognition of anthropology, the promotion of Dr. Franz Boas to a profes- 
sorship in Columbia University, does just honor to one who began his 
academic career as a Decent in Clark University in 1890. How much of 
the interest in anthropology in other institutions of learning can be legiti- 
mately traced to this University, which, in 1892, conferred the first Ph.D. 
ever granted in America for research and investigation in anthropological 
science, cannot readily be ascertained, but its influence, both direct and 
indirect, has been, no doubt, as it still is, very great. Proofs of this are 
not wanting in the curricula of more than one of the higher institutions 
of learning, while the course in anthropology in the University of Illinois, 



* Anthropology. 157 

offered by Dr. Arthur H. Daniels, a graduate of Clark University, is 
directly due to the initiative and encouragement of the department of 
anthropology. 

Through the lectures delivered at the University and during the 
Summer School, the anthropological department has exercised an ever 
increasing influence, which has been added to by the appearance of one 
series of these lectures in book form. Another point of contact with the 
teaching profession throughout the country lies in the use of the depart- 
ment as a sort of bureau of information upon many and varied topics of 
educational science. During the last year, especially, very many requests 
for such information have been received and responded to, often in detail 
and as the result of personal research. To the students of the University 
the department of anthropology has always emphasized the great value 
of a bibliographical knowledge of the subject under investigation, and 
its services have always been at their disposal. 

In this University anthropology ranks as a branch of psychology, and 
to promote and advance it as such has been the constant aim and endeavor 
of its representative on the Faculty. The lectures have been such as to 
correlate with the instruction given in philosophy, psychology, and peda- 
gogy, and their object has been to furnish the students in those depart- 
ments with the most recent results of anthropological investigations, and 
to imbue them with that wider and deeper thought that comes from the 
contemplation of the history of individual and of racial man, and to lay 
firm foundations upon which in years to come may rise a complete and per- 
fectly equipped department of anthropology. A glance at the theses and 
essays in the departments of philosophy and psychology will demonstrate 
the way in which the department has advantaged those who have pro- 
ceeded to their degrees in this University, such subjects as " Regeneration," 
"Dolls," "Migration," "Hydro-Psychoses," " Dendro-Psychoses," "Im- 
mortality," " Teaching Instinct," " Philosophy of Education," "Adoles- 
cence," "Degeneracy," etc., naturally calling upon anthropology for its 
quota of fact and information, which has often been quite large and sig- 
nificant. Especially has this been the case since " Child-study" has loomed 
up so largely in the field of education, for questions of heredity and environ- 
ment, recapitulation, atavism and reversion, degeneration, variation, genius, 
and the like, must receive from anthropology, more or less, their true 
orientation and interpretation, — the science of the child would be help- 
less without the science of man, the story of the individual not half 



158 Anthropology. 

understood without the story of the race. The greater prominence now 
being given to individual psychology, brings psychology also into closer 
and better touch with anthropology. That the first woman to hold a 
fellowship in any department in Harvard University was an anthropolo- 
gist is a fact, which, taken in connection with the great amount of excel- 
lent original work done in anthropology by women, both in Europe and 
in America, augurs well for the future advancement of the science, when 
all institutions offering post-graduate instruction in anthropology and 
facilities for original investigation shall have been opened to women upon 
the same terms as to men. The composite character of the population of 
the United States, the existence within its borders of several entirely dis- 
tinct races, and the addition to these resulting from the recent acquisition 
of outlying and distant possessions, must inevitably tend to make anthro- 
pology more and more a real academic necessity, no less than a constant 
factor in the determination of national welfare and progress. Unless 
every sign fails, the history of anthropology in the next quarter century 
of American university life will compare in brilliancy with that of any 
other science similiarly stimulated and environed. 

At this University, anthropology has accomplished, as the record of 
the publications of the department shows, results out of proportion to its 
financial resources and the facilities for investigation and research made 
possible thereby. With other departments in the University it has striven 
to overcome these serious handicaps as much as might be, and what has 
already been done must serve to indicate what can be done in the future, 
if the department is generously and satisfactorily endowed. Nowhere 
else, perhaps, can the " sinews of science," rightly employed, give ampler 
or juster returns, if the past foreshadows the years to come. 

Clark University, the first institution in America to recognize anthro- 
pology as a fit and proper subject for post-graduate researches and inves- 
gation leading to the degree of Ph.D., and the first university to confer 
such a degree, can justly hope for that recognition which comes to the 
pioneers in all great educational movements. 

But before the department can labor at its best, it must have the best 
means of research and investigation, be equipped as well, at least, as any 
similar department in any other institution in the country. Given these, 
it can do as good work, or even better. 

The professorships at Harvard, Columbia, Chicago, and Pennsylvania, 
the Thaw Fellowship at Harvard, the library of 20,000 books and pam- 



Anthropology. 159 

phlets in a single branch of anthropology at the University of Pennsyl- 
vania, and the laboratory and museum facilities of all these institutions 
which have come into such rich fruition during the last ten years, jpoint 
the way for us, if the good work of the past is to increase and multiply. 
For comparison with the present state of affairs at this University, the 
following data from the most recent official publications of the universi- 
ties concerned, institutions which offer post-graduate courses in anthro- 
pology and confer the degree of Ph.D. in that department, will suffice 
(sociology, etc., not included): — 

Harvard: Professor; Instructor; Thaw Fellow ($1050); Hemenway Fellow 

($500) ; Winthrop Scholar ($200). 
Chicago : Associate Professor ; one Fellow. 
Columbia : Professor ; two Instructors ; President's University Scholar ($150) ; 

one Fellow ; two Scholars. 

One cannot escape seeing the necessity of enlargement and further 
endowment at tliis University, if anthropology is to prosper fully. 

Before the great things of which it is capable can, in all their rounded 
completeness, be accomplished here, changes and improvements must 
take place, and the following are among those most needed or most 
desirable : — 

(1) The department must ultimately be dignified by the existence 
of a professorslup, if it is to continue to hold its own among the similar 
departments in other great educational institutions. Anthropology can 
wait, as it has waited, but it scarcely deserves that refusal of academical 
advancement, which is, of necessity, bound up with straitened financial 
conditions. 

(2) A complete departmental library, which shall include all cur- 
rent periodicals and journals of anthropological interest and afford imme- 
diate access to the very latest American and foreign publications in all 
branches of anthropological science, is an absolute necessity. The ad- 
vantage of having all these under one roof and procurable immediately 
after their issuance is inestimable. 

(3) A thoroughly equipped laboratory, for special researches and 
investigations, is also among the things first to be desired, and what 
investigators now, or formerly connected with the University, have done 
in this field is a full guarantee that such an addition to the facilities of 
the University would be well utilized and appreciated. 



160 Anthropology. 

(4) A museum, which shall contain materials and specimens illustrating 
the parallel development of the individual and the race, is also a desidera- 
tum, for this truly anthropological theory, so fecund for education and 
psychology, has yet to undergo that stern test which zoology, palseon- 
tology, and geology have so successfully sustained. 

(5) Generous endowment of fellowships and scholarships (intra-mural 
and extra-mural) and other aids in investigation and field work is abso- 
lutely necessitated by any adequate instalment of anthropology. 

(6) More, perhaps, than is the case with most other departments, lib- 
eral allowances for clerical work and for travelling expenses, the lack of 
which so often delays good studies and inconveniences good men, are nec- 
essary, and the department must be congratulated on what has been 
achieved in the absence of all these. Often to be able means to accomplish. 

Judged both by the work accomplished here and the status of anthro- 
pology in other universities, the department has every reason to ask 
and every right to expect such increased endowment as will enable it to 
make the next ten years of its existence as notable as the same period in 
the history of anthropology in any of the higher institutions of learning, 
European or American. 



PEDAGOGY. 

By William Henry Burnham. 

Soon after the opening of the University, President G. Stanley Hall 
entered upon the duties of Professor of Psychology and Education. 
During the first academic year no pedagogical courses were given, but 
toward the close of the year Dr. William H. Burnham, the writer of this 
report, was appointed Decent in Pedagogy and sent to Europe by the 
University to study educational institutions, methods, etc. Diuing the 
year 1890-91, courses of lectures on pedagogy were given in the psycho- 
logical department by Drs. Hall and Burnham, and a seminary met weekly 
for the study and discussion of educational subjects. In 1893 the educa- 
tional courses were designated as a sub-department of psychology offering 
a minor for the doctor's degree. But the work has remained most inti- 
mately connected with that in psychology and anthropology. 

In any natural development of these three subjects, the subject-matter 
overlaps and is interrelated. In this University no attempt has been 
made to mark a line of division between them. Specially close has been 
the connection between psychology and pedagogy, most of the students 
in one subject taking courses in the other. Such vital connection of the 
two subjects has mutual advantages. Pedagogy is based upon psychology 
and owes to it the inspiration and stimulus to scientific work, and psy- 
chology owes to pedagogy the suggestion of some of its most fruitful 
fields of investigation. 

With a limited staff no attempt has been made to cover the whole 
field of pedagogy ; but by choosing specially important parts of the field, 
and by extending the courses over two or three years, an effort has been 
made to show how the subject should be studied. By this method lectures 
have been given on the history of the modern reform movement in educa- 
tion, begun on the one hand by the early Italian Humanists, and on 
M 161 



162 Pedagogy. 

the other by Comenius, the present organization of schools in England, 
France, and Germany, the Evolution of the Teaching Profession, the 
Historical and Critical Study of Educational Principles, Mental and 
Physical Development, Educational Psychology, and School Hygiene, 
including the Hygiene of Instruction. Other courses have been given 
by Drs. Hall, Burnham, and Lukens on the following among other 
topics : History of Methods in Reading, Physical Education, Child-study, 
Adolescence, Ideal School, Herbartian Pedagogy, History of Curricula, 
and leading present topics in education. 

A great variety of subjects have been studied in connection with the 
seminaries, and the results of many of these studies have appeared in the 
Pedagogical Seminary, an educational journal edited by G. Stanley Hall 
and published at the University, beginning in 1891. The work of the 
department is best seen, however, by noting its aims, methods, and 
concrete results. 

The aim of the department is twofold : first, to give instruction and 
training to those who are preparing to be professors of pedagogy, super- 
intendents, or teachers in higher institutions ; second, to make scientific 
contributions to education. These two ends are so closely related that 
the pursuit of one involves much of the work required for the other also. 
Suitable preparation for the course involves so much of general edu- 
cation as is usually indicated by the B.A. degree. A good reading 
knowledge of French and German is of vital importance, and an acquaint- 
ance with elementary psychology is desirable, it being taken for granted, 
of course, that those who intend to teach have adequate knowledge in 
their own special departments. 

Assuming that a student has adequate preparation, three things are 
essential for higher pedagogical training : first, a general knowledge of 
the organization of education in different countries and of literature in the 
field of education, including the history of ediication, psychology in its 
relation to education, and school hygiene; second, actual experience in 
teaching, together with observation of good teaching, and some direct 
study of educational institutions of different character and grade ; third, 
some experience in independent research, involving not only the thorough 
study of all authorities upon a subject, and of all work that has been done 
in the same field in different countries, but also original investigation 
leading to a scientific contribution. 

These three kinds of work may be done simultaneously or successively. 



Pedagogy. 163 

In some of the best higher pedagogical seminaries in Germany they are 
done simultaneously. Students study and report upon educational and 
psychological literature. They visit classes of different grades, observing 
the work of regular teachers, and also teach in a practice school. At the 
same time they endeavor to investigate some special problem. In this 
University the study of educational literature, by lectures and inde- 
pendent reading, and the investigation of some problem, are usually car- 
ried on simultaneously ; but practical experience in teaching must be 
gained before or after the University course. There are some advan- 
tages in doing actual teaching simultaneously with the study and investi- 
gation of educational problems. Direct experience in the school makes 
investigation more vital and practical, and is an important control in 
scientific research. But, while at present the University has no practice 
school, as a matter of fact, most of those who have been members of the 
educational department have had experience in teaching before coming 
to the University ; and the lack of direct connection with the schools is 
in part supplied by visits to educational institutions. Moreover, there 
is no rigid line between instructors and students in the department. Both 
are teachers and learners in turn. Special emphasis is placed upon the 
importance of research ; and much of the time of the instructors is spent 
in consultation with individual students in regard to their investigations. 
President Hall especially has given a large amount of attention to direct- 
ing this work. The research undertaken has been largely in the field 
of genetic psychology and related subjects ; and the students have 
been assisted by the instructors in psychology, anthropology, and neu- 
rology. A great variety of topics, however, have been studied; and 
a large part of the investigations have yielded results for publication. 
The papers^ that have already appeared may be roughly classified as 
follows : — 

Contributions to the Physiology and Psychology of Development. 

BOHANNON, E. W. : A Study of Peculiar and Exceptional Children. 
Pedagogical Seminary, Oct., 1896, Vol. 4, pp. 3-60. 

Based upon answers to a questionnaire reporting over a thousand 



1 Many of the papers mentioned in this list are quite as much products of the department 
of psychology as of that of pedagogy ; and, on the other hand, the pedagogical department 
has contributed to many of the psychological studies mentioned above. 



164 Pedagogy. 

BoHANNON, E. W. : The Only Child in a Family. Pedagogical 
Seminary, April, 1898, Vol. 5, pp. 475-496. 

Erom a study of reports of 381 only children, it appears that only chil- 
dren are below the average in vitality and unusually subject to mental 
and physical defects of a grave character, and that, lacking the impor- 
tant education from the constant companionship of other children, they 
need special pedagogical care and training. 

Btjek, Feedbeick : Growth of Children in Height and Weight. 
Am. Jour, of Psy., April, 1898, Vol. 9, pp. 253-326. 

A comprehensive resume of the numerous studies in this field, with a 
discussion of their pedagogical significance. 

BuEK, Feedeeick : From Fundamental to Accessory in the Devel- 
opment of the Nervous System and of Movements. Pedagogical 
Seminary, Oct., 1898, Vol. 6, pp. 5-64. 

A contribution to the physiology of development, especially a study 
of the evolution of hand movements in the development of the normal 
child. From a comprehensive review of the various neurological and 
psychological studies upon this siibject, the author makes among others 
the following conclusion : that there is an early period in the develop- 
ment of each part or process when the purpose of education must be to 
follow the fixed innate heredity line of tendency (fundamental educa- 
tion); that there follows a later period in an activity's development 
when it passes partially out of the control of racial habit and becomes 
more plastic to present environment (accessory education). Presented 
as a dissertation. 

BuRNHAM, Wm. H. : The Study of Adolescence. Ibid., June, 1891, 
Vol. 1, pp. 174-195. 

A brief introduction to the study of the adolescent problem. 

BuENHAM, Wm. H. : Individual Differences in the Imaginations of 
Children. Ibid., March, 1893, Vol. 2, pp. 204-225. 

Based upon literature and reports by students at the Worcester 
Normal School. 

Cheisman, Oscae: The Secret Language of Children. Science, 
Dec. 1, 1893, Vol. 22, p. 303. 



Pedagogy. 165 

Ceoswell, T. R. : Amusements of Worcester School Children. 
Pedagogical Seminary, Sept., 1899, Vol. 6, pp. 267-371. 

A study of tlie amusements of two thousand children based upon 
reports by the children. A contribution to the problem of variation in 
play as conditioned by age, sex, nationality, locality, and season. The 
results indicate as characteristic of the games of adolescence the coopera- 
tion of a number of individuals to secure a definite end, and the delight 
in contest in contrast with the individualistic amusements of earlier 
years. 

Hall, G. Stanley: Initiations into Adolescence. Proc. Am. 
Antiq. Soc, Worcester, Mass., Oct. 21, 1898, Vol. 12, pp. 367-400. 

Includes a detailed account of certaia rites of primitive peoples, and 
discusses the relation of adolescent instincts in religion. 

Lancaster, E. G. : The Psychology and Pedagogy of Adolescence. 
Pedagogical Seminary, July, 1897, Vol. 5, pp. 61-128. 

A comprehensive study by the questionnaire method. With a resumd 
of the work of others and practical suggestions. Presented as a disser- 
tation. 

YoDER, A. H. : The Study of the Boyhood of Great Men. Ihid., 
Oct., 1894, Vol. 3, pp. 134-156. 

Based upon the study of a large number of biographies. 

Studies of Special Branches of Education from the Genetic Point of View. 

Ellis, A. Caswell : Sunday-school work and Bible Study in the 
Light of Modern Pedagogy. Ibid., June, 1896, Vol. 3, pp. 363- 
412. 

An attempt to suggest the psychological method of religious instruc- 
tion, together with an historical sketch of the Sunday-school idea. 

Johnson, G. E. : Education by Plays and Games. Ibid., Oct., 1894, 
Vol. 3, pp. 97-133. 

Presents a classified list of about five hundred plays and games with 
a study of their educational value. 

HOYT, Wm. a. : The Love of Nature as the Root of teaching and 
learning the Sciences. Ibid., Oct., 1894, Vol. 3, pp. 61-86. 
Based chiefly upon literature, with pedagogical suggestions. 



166 Pedagogy. 

Ltjkens, Herman T. : Preliminary Report on the Learning of Lan- 
guage. lUd., June, 1896, Vol. 3, pp. 424-460. 

Traces the stages in a child's learning to talk, and presents much data 
in regard to pronunciation and the development of the sentence. 

LuKENS, Herman T. : A Study of Children's Drawings. Ihid., 
Oct., 1896, Vol. 4, pp. 79-110. 

A genetic study based upon original reports and observations. 

Phillips, D. E. : Number and its Application psychologically con- 
sidered. Ihid., Oct., 1897, Vol. 5, pp. 221-281. 

Includes a study of over two thousand arithmetic papers prepared 
by children in the schools, the results of a questionnaire research, a criti- 
cal estimate of many text-books, and a discussion of the general sub- 
ject from the genetic standpoint. 

Street, J. R. : A Study in Moral Education. Ibid., July, 1897, 
Vol. 5, pp. 5-40. 

Based upon the reminiscent answers of adolescents to a questionnaire. 
The results suggest the great role of imitation, instruction, the sentiments, 
and heredity in moral action, and emphasize the significance of habit. 

Street, J. R.: A Study in Language Teaching. Ibid., April, 1897, 
Vol. 4, pp. 269-293. 

Studies in School Hygiene. 

BuRNHAM, Wm. H. : Outlines of School Hygiene. Ibid., June, 
1892, Vol. 2, pp. 9-71. 

Includes, besides a general survey of school sanitation, brief studies 
of such topics as fatigue, the period of study, school furniture, the 
hygiene of writing, etc. 

Burnham, Wm. H. : Bibliography of School Hygiene. Proc. N. 
U. A., 1898, pp. 505-523. 
A selected list of 436 titles. 

Chrisman, Oscar: The Hearing of Children. Pedagogical Semi- 
nary, Dec, 1893, Vol. 2, pp. 397-441. 

A resume of the investigations of the hearing of school children in 
different countries. Practically complete to the date of publication, with 
practical suggestions collected from different authorities. 



Pedagogy. 167 

Dkesslar, F. B. : Fatigue. Ibid., June, 1892, Vol. 2, pp. 102-106. 

An introduction to the general subject of mental fatigue. 

Deesslae, F. B. : A Sketch of Old Schoolhouses. Ihid., June, 
1892, Vol. 2, pp. 115-125. 

A brief historical contribution to school hygiene. 

Principles, Methods, and Organization of Education. 

Ceoswell, T. R. : Courses of Study in the Elementary Schools of 
the United States. Ihid., April, 1897, Vol. 4, pp. 294-335. 

Devoted especially to state and city courses and legal requirements. 

Ellis, A. Caswell : Suggestions for a Philosophy of Education. 
Ihid., Oct., 1897, Vol. 5, pp. 159-201. 

The closing chapter of an extended historical study of the philosophy 
of education presented as a dissertation. 

Hall, G. Stanley : Child Study the Basis of Exact Education. 
Forum, Dec, 1898, Vol. 16, pp. 429-441. 

LuKENS, Heeman T. : The Correlation of Studies. Educational Re- 
view, Nov., 1895, Vol. 10, pp. 364-383. 

Pottee, J. R. : History of Methods of Instruction in Geography. 
Pedagogical Seminary, Dec, 1891, Vol. 1, pp. 415-424. 

Specially an account of German methods, based upon literature. 

ScEiPTUEE, E. W. : Education as a Science. Ihid., June, 1892, 
Vol. 2, pp. 111-114. 

A plea for experimental education with report of illustrative experi- 
ments. 

Seaes, Chaeles H. : Home and School Punishments. Ihid., March, 
1899, Vol. 6, pp. 159-187. 

Based upon literature and the answers to a questionnaire. 

The Training of Teachers. 

BuEK, Feederick L. : The Training of Teachers. Atlantic Monthly, 
Oct., 1897, Vol. 80, pp. 547-561, and June, 1898, Vol. 81, pp. 
769-779. 



168 Pedagogy. 

Btjknham, Wm. H. : Higher Pedagogical Seminaries in Germany. 
Pedagogical Seminary, Dec, 1891, Vol. 1, pp. 390-408. 

A sketch of the history and present character of the different kinds 
of pedagogical seminaries for training teachers for the higher schools in 
Germany, based on literature and personal observation. 

Btjbnham, Wm. H. : Some Aspects of the Teaching Profession. 
Forum, June, 1898, Vol. 25, pp. 481-495. 

Hall, G. Stanley : American Universities and the Training of 
Teachers. Ihid., April and May, 1894, Vol. 17, pp. 148-159, 
297-309. 

Hall, G. Stanley: The Training of Teachers. 75ii., Sept., 1890, 
Vol. 10, pp. 11-22. 

Hall, G. Stanley : Research the Vital Spirit of Teaching. Ihid., 
July, 1894, Vol. 17, pp. 558-570. 

Phillips, D. E. : The Teaching Instinct. Pedagogical Seminary, 
March, 1899, Vol. 6, pp. 188-245. 

A study of the phenomena of leadership and teaching among animals 
and children, of the lives and motives of the great teachers, and of train- 
ing in relation to the teaching instinct, including a contribution by the 
questionnaire method. Presented as a dissertation. 

Reigaet, J. F. : The Training of Teachers in England. Ihid., Dec, 
1891, Vol. 1, pp. 409-415. 

A brief sketch based upon literature. 

Miscellaneous. 

BuKK, Feedeeick L. : Teasing and Bullying. Pedagogical Seminary, 
April, 1897, Vol. 4, pp. 336-371. 
Based on returns to a questionnaire. 

Hall, G. Stanley : Boy Life in a Massachusetts Country Town 
Thirty Years Ago. Proc. Am. Antiq. Soc, Worcester, Mass., Oct. 
21, 1890, N. S., Vol. 7, pp. 107-128. 

An historical contribution showing the many-sidedness of the home 
education of the New England country boy. 



Pedagogy. 169 

Hall, G. Stanley: The Case of the Public Schools. Atlantic 
Monthly, March, 1896, Vol. 77, pp. 402-413. 

Hall, G. Stanley : The Love and Study of Nature : a Part of 
Education. Agriculture of Massachusetts, 1898, pp. 134-154. 
Lectures delivered before the Massachusetts State Board of Agri- 
culture at Amherst, Dec. 6, 1898. 

Treats of the child's attitude toward nature. 

Hancock, John A. : An Early Phase of the Manual Training Move- 
ment. Ibid., Oct., 1897, Vol. 5, pp. 287-292. 

A brief historical sketch of the old manual labor school. 

Johnson, G. E. : Contribution to the Psychology and Pedagogy of 
Feeble-minded Children. Ibid., Oct., 1895, Vol. 3, pp. 246-291. 

Reports result of tests of memory span, motor ability, and association, 
in feeble-minded children at the Massachusetts School for the Feeble- 
minded at Waltham, together with an historical iatroduction and practi- 
cal suggestions for their education. 

KiSTLBK, Milton S. : John Knox's Services to Education. Education, 
Oct., 1898, Vol. 19, pp. 105-116. 

Kline, Linus W. : Truancy as Related to the Migratory Instinct. 
Pedagogical Seminary, Jan., 1898, Vol. 5, pp. 381-420. 

Includes a comparison of the physical condition of truants as shown 
by anthropometric tests with that of public school children. 

Sheldon, Heney D. : The Institutional Activities of American Chil- 
dren. Am. Jour, of Psy., July, 1898, Vol. 9, pp. 425-448. 
Based largely on returns to a questionnaire. 

Small, M. H. : Methods of manifesting the Instinct for Certainty. 
Pedagogical Seminary, Jan., 1898, Vol. 5, pp. 313-380. 

A comprehensive study of oaths based upon 2,263 answers to a ques- 
tionnaire and a vast amount of literature. 

Such have been the methods of the department, and such in part the 
work done. The aim has been to treat a few subjects in a broad way, 



170 Pedagogy. 

rather than to exhaust the field of conventional pedagogy. The necessity 
and the advantages of this method are obvious from a brief consideration 
of the subject of education, both theoretical and practical. 

Jean Paul Richter quotes the French artist who required from a good 
director of the ballet, besides the art of dancing, only geometry, music, 
poetry, painting, and anatomy. " But," he adds, " to write upon educa- 
tion means to write upon almost everything at once ; for it has to care for 
and watch over the development of an entire . . . world in little, — a 
microcosm of the macrocosm. ... If we carried the subject still fur- 
ther, every century, every nation, and even every boy and every girl, 
would require a distinct system of education, a different primer and do- 
mestic French governess, etc."^ The subject of pedagogy is still more 
encyclopaedic to-day than when Jean Paul Richter wrote these words. 
Its foundation involves the whole physiology and psychology of develop- 
ment in the individual, and the history of culture in the race, and its 
superstructure includes, not only all the various forms and systems and 
methods of education, but the study of the influence of environment in 
the widest sense. 

The conventional views minimize both the difficulties and the impor- 
tance of the subject. It is said that pedagogy is applied psychology or 
applied child study, and again that pedagogy must get its norms from the 
history of education and from child study. This statement will do if one 
knows what it involves. The history of education means the history of 
civilization from its earliest traceable genesis among primitive peoples. 
It means a study of types of culture and the conditions of their develop- 
ment. In a word, it is a study of the evolution of education. Child 
study means, too, the study of the physiology and psychology of develop- 
ment in man. The science of development aims to give a complete 
description of all the stages of physical development from infancy to 
maturity, to show their sequence and their relation to the acquisition of 
organic, sensory, motor, and psychic processes. As far as psychology goes, 
it is genetic psychology, which means more than is frequently connoted 
by child study. Adult psychology is one thing, relatively fixed, except 
for variations incident to environment or the individual. Child psychol- 
ogy, even for a single individual and a given environment, varies con- 
tinually because the individual is in the process of growth and rapid 
development of function. It is one thing for the infant, a very different 

1 Eiohter, " Levana, or the Doctrine of Education," Author's Preface. 



Pedagogy. 171 

thing for the child who can walk and talk, still another at that plateau in 
the curve of development that seems to come somewhere between nine 
and twelve for girls and ten and fourteen for boys, still another for the 
adolescent. The variation is seen in the period of a single year, almost 
with the changing moons. This is true, not only on account of the grosser 
acquisitions, but is seen in the sequence of interests and activities. Child 
psychology is protean. It varies not only with the individual and the 
environment, but especially with the stage of development. Further, the 
science of development includes comparative psychology. Not only must 
the child mind be compared with the adult mind, but the stages of devel- 
opment in the child should be compared with the stages of development in 
animals, the faculties of the child with those in animals, the motor ability 
and activities of the child with those in animals. And again, the stages 
of development in the child must be compared with those in the race; 
ontogenesis in relation to phylogenesis must be studied. 

All this is scientific study, not directly practical. Before deriving the 
norms for practical pedagogy, a propaedeutic study must be made. As 
Professor James has said: " Psychology is a science, and teaching is an 
art; and sciences never generate arts directly out of themselves. An 
intermediary inventive mind must make the application by using its 
originality." This mediating function is represented by two somewhat 
vaguely defined branches of pedagogy — educational psychology, and the 
general principles and methods of education. 

Again, after the general principles of education have been derived from 
psychology and history, and the theoretical norms established, they must 
be verified by practical educational experiments. This brings us to the 
practical side of pedagogy represented by such subjects as the organizar 
tion of schools, the art of teaching, and special didactics. And parallel 
with the art of teaching in its derivation from the science of development 
is school hygiene, which studies especially the conditions that favor the 
healthy development of the school child. Thus pedagogy is both theoreti- 
cal and practical, at once a science (at least potentially) and an art. 

Such is the subject which, as the Italian proverb runs, is always poor 
and naked, and, in the words of a German writer, has long sat as a drudge 
at the academic hearth, and whose highest recognition in the great univer- 
sities has usually been as the handmaid of philosophy. Everybody 
believes in education, yet few believe in pedagogy. The reasons for this 
are obvious. Apart from a few fundamentals that are almost common- 



172 Pedagogy. 

place, pedagogy has lacked a solid body of scientific knowledge and 
universally accepted principles. Worse than this, it has lacked a definite 
method and a definite ignorance. 

Most of the works on the history of education are padded with accounts 
of second-rate writers and second-rate books that happen to be labelled 
educational ; while the really great educators have often been neglected, 
and educational movements have been described as isolated currents in 
the progress of civilization, without regard to their vital connection with 
political, social, and industrial movements. The method has been the 
elementary method of studying and describing isolated facts without 
regard to historical perspective and causal relations; and even the works 
of the classic writers have been chiefly the repetition and recasting of a 
few old truths which had been forgotten or were ignored at the time in 
which the reformers lived. For example, Comenius two hundred and fifty 
years ago taught that we must study nature by the inductive method 
and adapt education to the sequence of the stages of natural development; 
but his writings were forgotten, and again and again the reformers have 
had to teach again to a new generation the simplest principles of the 
Comenian didactic. Most of the books on the educational systems of 
to-day, in like manner, consist of the barren details of organization and 
method, and the description often of inferior teachers and schools. The 
forces that have produced these teachers and schools, the significance of 
the educational movements, have not been seen; and the philosophical, 
social, and religious thought that has determined educational ideals has 
not been studied. These isolated facts are barren. Their real signifi- 
cance is in their relation to other facts. We cannot, for example, under- 
stand the educational events in England to-day unless we know something 
of the wider relations of the school movement. The wrangling over the 
question whether the parish of Eastbourne shall have a school board, 
or whether the school education of the parish shall continue to be supplied 
by voluntary schools, means a great deal more than a difference in taxes 
of a few pence in the pound. This petty struggle is a part of the great 
movement for the disestablishment of the Church of England. The com- 
missioning of a new fellow for university extension work marks another 
step in the progress of the democratic ideal, which, no longer satisfied with 
provision for elementary education for every child, now demands also for 
each individual, according to his ability, a share in higher education. A 
new endowment for a technical school by the Worshipful Society of Gold- 



Pedagogy. 173 

smiths, or the like, may indicate a new dread of democracy on the part of 
certain monopolists quite as much as any special interest in industrial 
education. Oxford itself, with all its marvellous beauty and idealism, the 
stronghold of conservatism, cannot keep aloof from the great social, indus- 
trial, and educational movements outside. No better illustration could be 
chosen to show the progress of the democratic ideal in education. At the 
beginning of Queen Victoria's reign one could not even study at Oxford 
without subscribing to the Thirty-nine Articles. A few years ago Jowett 
advocated opening the university honors and emoluments to the world, 
admitting anybody to any university examination without restriction of 
' sect, class, race, age, or residence. As was remarked at the time, if fifty 
or perhaps twenty years ago a radical undergraduate were to have made 
such suggestions, he would have stood a chance of being expelled from the 
university, as Shelley was, for blasphemy; now they are the last words 
of Jowett, quoted with approval before the vice-chancellor. 

To miss these larger aspects is to miss everything of permanent value. 
Historical literature in education has relatively little importance for its 
direct practical teachings ; but the importance of the history of education 
as a culture subject can hardly be put too high. Education represents 
one of the deepest human interests, more vital than politics, and well- 
nigh as universal as religion. The history of education is the history of 
the development of civilization. It aims at nothing less than the study 
of the school as a factor in the development of culture in relation to the 
other factors in education, — the home, the church, the farm, the work- 
shop, the playground, and the rest. And it aims at the study of educa- 
tional movements in their genesis, and in relation to political, social, 
industrial, scientific, and literary movements. This involves not merely 
the study of educational writers so-called and school systems, but the 
study of types of culture and the causes that condition them. 

Likewise in the other parts of the field the failure to recognize the 
wider significance of the subjects studied, and the attempt to build sys- 
tems before the foundations were laid, have brought pedagogy into disre- 
pute. But in recent years the conviction has grown that educational 
problems must be studied inductively ; and, better still, important contri- 
butions by the inductive method have actually been made. This has put 
life into the subject and given hope for the future. Take child study as 
an illustration. The significance of the modern study of children is not 
merely the renewed emphasis on the old truth of adapting education to 



174 Pedagogy. 

the stages of development, but the insight that the only way to make this 
principle vital is concrete inductive study to find out just what are the 
stages of natural development. Thus every fact in regard to general 
development or individual variation is deemed significant, and the student 
is willing to wait for a new science of development before attempting a 
permanent pedagogical system. 

During the past ten years the opportunities for truly scientific work 
in education have been shown as never before, methods of investigation 
have been demonstrated, and in part the foundations of a science have 
been laid. The things now needed are trained men and facilities. With 
them a solid content of scientific knowledge can be acquired that will 
place historical and social pedagogy on as firm a basis as general history 
and sociology, and genetic pedagogy on a scientific footing comparable to 
that of psychology. School hygiene has already its methods and a soKd 
body of knowledge, but it needs special laboratories for instruction and 
research, either independent or in connection with psychology, physiology, 
and anthropology. 

The work in pedagogy in this University, although the practical 
aspects of the subjects studied have not been neglected, has been chiefly 
in the more scientific and theoretical parts of the field. It is not less 
important on this account. Pedagogical study, like research in any 
other field of history or science, is valuable for its own sake without 
regard primarily to practical results. It is its own justification and its 
own reward. With the nucleus of solid scientific contributions that now 
exists, no university can long afford to omit courses in education from its 
curriculum, whether they have any practical value or not. Such scien- 
tific studies, however, cannot be divorced from the practical art of educa- 
tion. The studies of children have emphasized the doctrine that the aim 
of childhood is its own development, and the best guarantee of normal 
maturity is normal childhood and immaturity ; in a word, they have 
emphasized the principles of normal development. But these principles 
are no longer pedagogical abstractions ; they are greatly modifying the 
practical work of education, causing greater regard for individual chil- 
dren rather than uniform classes, for health rather than scholastic prod- 
ucts, for a psychological order of instruction adapted to the capacity and 
interests of children rather than logical sequence and articulation of 
grades. In a word, they are causing courses of study and methods to be 
reconstructed with regard to the one fundamental principle of fostering 



Pedagogy. 175 

normal growth and development. To mention a few details, ten years 
ago school baths, adjustable seats and desks, and vertical script, were 
vagaries of university theorists ; to-day they are deemed essentials in 
the best schools. Ten years ago suggestions of periodic disinfection of 
school apparatus and school text-books, of investigating pupils' individual 
capacity and power to resist fatigue, and of adapting education to iudi- 
vidual capacity and interest, in elementary and secondary schools, were 
likely to be ridiculed ; now their soundness has been demonstrated by 
practical experiments. 

What part this University has had in this movement, it is not easy 
to say ; but it has always advocated such reforms in the regular courses 
of lectures ; many addresses on topics in school hygiene and pedagogy have 
been given outside the University before schools and teachers' meetings ; 
students from this University have become school superintendents, teachers 
in secondary schools, professors of pedagogy or psychology in normal 
schools, professors of pedagogy in colleges and universities ; and teachers 
and educators from all parts of the country have attended lectures on 
pedagogy during the sessions of the Summer School. 

To make a department of pedagogy what it should be, it is necessary 
that the whole field of education be covered by lectures as far as possible, 
that the more elementary courses be given every year, that research 
should be extended to the multitude of topics that offer opportunity 
for study. Nowhere in the world is a complete course in pedagogy 
covering all the important parts of the field given. Here and there 
throughout this country and Europe are offered a few truly scientific 
courses, but the subject will hardly attain its due academic dignity until 
somewhere in one university are given courses which approximate an 
adequate treatment of the whole field. That this University might 
approximate a complete course in the subject are needed an addition to 
the staff, especially for the study of historical and social pedagogy, the 
establishment of special fellowships for educational research, a laboratory 
for school anthropometry and school hygiene, a great enlargement of the 
educational museum, a pedagogical library like that of the Musee peda- 
gogique in Paris, where educational literature of every kind, both good 
and bad, may be collected ; and, finally, a model school for the objectifi- 
cation of ideals, under the direction of competent teachers who should 
safeguard the interests of the pupils, but offer to university students op- 
portunities for observation, and in some cases for practice in school work. 



176 Pedagogy. 

The aim of such a course in pedagogy, like that of the more limited 
course already given in this University, would be twofold : first, to con- 
tribute something to the body of knowledge in regard to education, the 
content of pedagogy ; and, second, to give practical training to students 
preparing to become teachers. These two aims are quite in harmony, 
for an essential in the training of a teacher is the development of those 
permanent professional interests and that professional apperception and 
prevision acquired by the study of the more scientific parts of pedagogy. 



PHILOSOPHY. 

By G. Stanley Hall. 

In addition to my own work in psychology and education, reported 
in the preceding articles by my colleagues, Drs. Sanford and Burnham, 
and in editing the American Journal of Psycliology and the Pedagogical 
Seminary, I have lectured during the last eight years on the History of 
Philosophy. This course is felt to be of cardinal importance for those 
studying either psychology or education, to give them breadth of view, 
to teach what great problems have interested the race, and to give a 
repertory of general ideas that will obviate some of the dangers of 
specialization. 

The course begins with a very brief survey of Oriental speculation, 
treats the pre-Socratic Greek thinkers with considerable detail and with 
constant reference to their fragmentary texts. Great stress is laid upon 
Plato, and from a quarter to half of all his works are read aloud by the 
students in turn from Jowett's translation, and on these dialogues the 
examination for the doctorate is in some part based. Even for those 
who read some Greek, the use of the English translation is preferred, 
because more can be gained from Plato by men of this grade by extensive 
reading than by intensive and critical study of text. Discussions often 
arise in this work. Aristotle is treated in the same manner, and selec- 
tions and sometimes large portions of some of his works are read in 
English. From twelve to twenty lectures are given on the later schools, 
ending with Plotenus and Proclus. This usually concludes the work of 
the first year. 

Until two years ago the second year began with the rise of scholasti- 
cism and the third ended with Schopenhauer, Lotze, Hartmann, and con- 
temporary writers. Special effort has always been made to go considerably 
outside the stock text-book field and to deal to some extent with the 
history of science, with some reference to medicine and with very slight 
reference to literature, art, etc. The texts of Spinoza, Locke, Berkeley, 
N 177 



178 Philosophy. 

Hume, Kant, Fichte, Schelling, Hegel, Schopenhauer, and Lotze have 
been used at different times and with very different results. Ethics, 
logic, metaphysics, and aesthetics are included in this course, and no 
special courses in any of these subjects have been given, although logical 
and ethical questions are treated in my psychological course. Considera- 
ble time is always given to epistemology. 

Two years ago, after considerable previous preparation, a course in 
Christology and Patristics was inserted between the ancient and the mod- 
ern course as above described. The life of Jesus was treated concisely 
and reverently from the standpoint of psychology, which is felt to be very 
different from that of the current lives of Jesus. This course, although 
at present being repeated with amplification, is still too incomplete to 
warrant any final report upon its utility. On the whole this historic 
course, which occupies three years, is earnestly recommended to all stu- 
dents of psychology, religion, education, or any of the humanities, and 
has generally been taken by all. 

During the past eight years I have opened my house one evening 
every week of the academic year to all students in the department of 
psychology and related themes from seven to ten o'clock. We began 
by discussing philosophical topics assigned beforehand to leaders in turn. 
One year most of the time of this seminary was devoted to reading 
and discussing Jowett's Plato. ^ Schopenhauer, Kant, and Hegel were 
tried for briefer periods, but gradually, as the numbers have increased 
and as the rule that each man should devote a portion of his time to some 
original investigation has prevailed, the evening has been occupied by 
each student in turn, who presents his thesis or subject, or a part of it, 
which is then freely discussed by the other members. The debates are 
often animated, as nearly every standpoint is represented. There are 
clergymen, young professors from other institutions, Hegelian idealists, 
Kantian epistemologists, and men of empirical science, and from these 
various directions nearly every subject is really illuminated. Attendance 
is never enforced, and the light refreshments served in the middle of the 
evening have never been an attraction, but only a welcome break from 
continued tension. The attendance for the last few years has rarely been 

1 See a somewhat disguised account of the first semester's work in two articles by H. 
Austin Aikins, entitled "From the Reports of the Plato Cluh." Atlantic Monthly, Sept. 
and Oct., 1894, Vol. 74, pp. 359-368, 470-480. 



Philosophy. 179 

under fifteen and rarely over forty, so that the entire freedom and infor- 
mality of conversation has been the rule. The themes assigned in a way 
described later have been presented here in so compact and forcible a 
way, that the seminary has been one of the most effective agents in my 
own education, and I think all its members share my sentiments in this 
respect. Here the new work on which each individual is spending so 
much of his year's time is pooled for the common benefit, the reader has 
the healthful stimulus of emulation in interesting his audience, acquires 
valuable practice in the methods of effective presentation, and always 
receives help in the way of new literature, references, the pointing out 
of defects in argument or method ; and conflicts are thus most surely 
avoided. Often other professors from the University attend, and the list 
of distinguished guests from abroad who have either participated in the 
discussions or introduced matter of their own is a long and dignified one. 
There is rarely any lack of interest or reluctance to discuss, and very 
infrequently is the animation too great for healthful mental circulation. 
Here nearly everything that has been done by the student members of 
this department of the University has been carefully wrought over, some 
of it more than once. 

Such stimulus I believe to be imsurpassed in educational value. The 
dialectic give and take of the conversational method, the mental alertness 
of debate, the charm of friendly intercourse upon high themes, which 
Lotze, like some of the ancients, thought the highest joy of life and the 
consummate fruition of friendship, are here combined in judicious propor- 
tions most favorable to growth. Some European seminaries are devoted 
to discussions of minute points ; in others the student is simply a literary 
forager for the professors ; quite frequently some author is read ; but for 
our American needs, at least for Clark University, I think the method 
now settled upon is more educative than any other that I have seen. 

A word should be said concerning student lectures. At various 
periods during the decade each member of the department has been 
requested to take his turn in presenting some subject in due form before 
the class, taking my place at the lecturer's desk, and developing his theme 
with the aid of charts, blackboard, and specimens if need be ; and at 
the close of the lecture I have a personal interview, stating very frankly 
any faults of manner, automatism, voice, method of presentation, etc., 
liable to interfere with his usefxilness as instructor or lecturer. More 



180 Philosophy. 

often, in place of an original lecture, each man takes his turn in digesting 
with extracts some book or chapter of a standard work in the history 
of philosophy, with the same criticisms. This personal relation together 
with the many hours spent each week with individuals, elsewhere spoken 
of, has been, I believe, of great value. 

At the beginning of the year (or, for those who have already spent a 
year at the University, near the close of the spring term) careftd lists of 
subjects which seem to the instructors in the department ripe for investi- 
gation are prepared. Each jots down all suggestions in this direction 
during the year, and all now meet to compare themes, consider whether 
they have already been treated, what new books and apparatus each will 
necessitate, by what paths each can best be approached and which are 
likely to yield the best and (what for thesis work is of great impor- 
tance) the most certain results of value. Conferences with each indi- 
vidual are then held and each is urged to select some theme, either 
because it is congenial or because it represents a field he desires to enter, 
and to devote some considerable portion of the year to the effort to 
master it and to add something new, however small, to the sum of the 
world's knowledge. 

A really good subject has aspects or divisions that bring the student 
into contact with each professor in the department, and each gives 
everything in the way of information, stimulus, and references that he 
possibly can. Our plan has always been to allow the student to print 
such work over his own name and to have full credit, although he usually 
makes acknowledgements at the close of his paper to his helpers. This 
plan we have found very congenial and stimulating to students, and it 
has avoided all questions of ownership rights in intellectual property. 
Again, a good subject must be midway between a very large and general 
and a very minutely special standpoint. The student must not waste his 
energy in vague generalities on the one hand, nor must he be shut up to 
some petty problem, perhaps fitting into and aiding the professor's special 
work, being thus unduly subordinated and apprenticed to him, as is so 
common in Germany. Fitting the problem to the man so that it will 
enlist all his interest and focus his knowledge and effort is half the work. 

In beginning more or less independent research like this, our best 
college graduates are often in a sense suddenly reduced back to infancy 
and need constant individual help to go alone. For the last ten years 



Pliilosopliy. 181 

most of several afternoons a week of my own time has been given in the 
laboratory, library, and conference room in trying to assist and direct 
young men to launch out in some modest yet effective way, as becomes 
them, on the great life of discovery. Some, often the best scholars, are 
so tied to authority that it is hard for them to be brought to realize that 
the best things have neither been done nor said in the world, and that 
mastery of the text-book is not final. Others are strongly inclined to 
repeat experiments, multiply observations, and accumulate numbers, and 
find it hard to make a serious study of the real significance of their 
data. Some approach subjects with preconceived ideas and speculate 
in a deductive way, abhorring details which others get lost in. Every 
type of philosophical opinion and every shade of temperament, every de- 
gree of intellectual enterprise at almost every rate of progress, is repre- 
sented. Some are strong in the literary, historical, and antiquarian side 
of their topic ; others in its experimental technique or in statistical pres- 
entation and tabulation or in literary form ; some at once tend to lose 
themselves in aspects of the subject that are so large that, instead of com- 
ing to a conclusion in an academic year, they begin to anxiously plan a 
life work and anticipate remote difficulties; while others can see abso- 
lutely nothing in topics of great range and significance except some over 
elaborately fortified or proven fact. 

This form of modern university work is a new kind of high Socratic 
midwifery, but in my opinion it is the most beneficial of all the points 
of contact between professor and student. Some must be encouraged; 
others must be roundly scolded. Some would devote all their time to an 
interesting work of this kind, while others dawdle with it as a mere side 
issue of doubtful educational value. A few do not want it, but are con- 
tented with receptivity of what others have done. Restless ones often 
seek change of theme, so that great discretion and great patience are 
needed in this work. 

Its rewards, however, are incomparably great. Having once discov- 
ered a fact or made ever so small an original contribution and had the 
baptism of printer's ink, the novitiate is henceforth a changed man. His 
ideals of culture, standards of attainment and excellence, and his methods 
of work are slowly revolutionized from this centre. Instead of being a 
passive recipient, his mind has tasted a free and creative activity which 
puts him on his mettle like the first taste of blood to a young tiger. He 
has learned that achievement and not possession is the end and aim ; his 



182 Philosophy. 

mind has been brought to a focus in such a way that he now knows what 
real concentration means as never before. He realizes that almost every 
subject in the universe, if broadly seen, is connected with every other, and 
that the cosmos, like his own mind, is knit together into a unity of a 
higher order. In all his works and ways he is more independent and more 
inclined to seek, do, know, and experience for himself. By such personal 
conference with individuals at all stages of their preparation in such a 
work, which need not be a doctor's dissertation and often is not, I am con- 
vinced, after a decade of experience here and some years of the same work 
at the Johns Hopkins, that this is the highest criterion of an academic 
teacher's real efficiency in his vocation, and that it is as much above the 
mass teaching of the lecture-room as talent is above mere learning. The 
necessity of this work is one of the chief reasons why truly university 
work must always be done, if not at small institutions, at least in squads 
so small that they can be thus individualized. 

Having brought this work to some degree of completion, as should be 
done at the close of each academic year, even at some sacrifice of scientific 
quality (because educational values should take precedence even over 
this, where the two conflict), an indispensable requisite is publicity and 
that without delay. Any institution or department that confers a doc- 
torate upon the ground of a dissertation that is unpublished conceals that 
upon which the chief value of the degree rests. The older the student 
the more stress should be laid upon this part of the work as compared 
with acquisition. In most departments, science is progressing so rapidly 
and work is so often duplicated that the necessity of announcing before- 
hand the theme of each research has often been urged, and any con- 
siderable interval between the completion of a work and its publication 
involves danger of anticipation by others, as well as general loss of value 
from the progress of science, which is always slowly leaving everything 
behind. Chiefly to avoid this danger the journals of this University 
were established, in which, without the cost to the students generally 
insisted upon elsewhere and with the advantage of a more or less extended 
international circulation among experts, everything can be speedily 
brought to the knowledge of those most interested and competent. To 
know that results will thus appear without delay is itself a real stimulus, 
and it is fortunate that evaluation of such work is coming to be a more 
and more prominent factor in determining appointments to university 
positions. The quality of mind which makes success here is infinitely 



Philosophy. 183 

more inspiring to students, even of lower grades, than the rehearsal of 
second-hand knowledge perhaps many removes from its source. Very- 
much might be said upon the effect of research as a stimulant to the 
teacher, while, from still another point of view, the fact that the instruc- 
tor has entered the great arena and submitted his productions to the 
critical estimate of experts, gives his pupUs confidence in him as an 
authority and not a mere echo. The provision of a sufficient number 
of reprints for circulation among special journals that will notice each 
work, and for exchange with other productive workers or departments, is 
another one of the new university problems unknown to the college, to 
the fuller exploitation of which the new journal here contemplated and 
elsewhere spoken of will be devoted. 

Great importance has always been attached here to the methods of 
bringing students into immediate and personal contact with the latest 
literature, especially upon the topics of their theses or those related to the 
original researches upon which they may be engaged. The exchanges of 
the journals constitute a carefully selected list of nearly three score peri- 
odicals, all of which, besides those regularly subscribed for by the library, 
are immediately available. Besides these the journals receive a large 
number of the most important books and pamphlets within their field, 
especially from American, English, French, and German houses. These 
works together with the smaller resources of my own library, which 
mainly supplements that of the University, are at the disposal of students, 
who are often encouraged to write brief book notices for publication. 
The frequent personal conferences with each student in the department 
keeps the instructor's mind alert to find out and bring to the immediate 
notice of each anything bearing upon his theme. Meetings are occasion- 
ally held in my library, where I spend the evening going through my 
shelves, taking out the books that I deem most important and that have 
helped me most, briefly characterizing each, and passing it around for 
actual inspection. If I had at my disposal an hour's time of a dozen of the 
most eminent men to utilize in such a way as would be of greatest benefit to 
me, I think I should ask them to do precisely this, for they would thus be 
giving me to some extent a key to their own intellectual activity and 
direction. Where this method is extended to monographs and pamphlet 
publications, the collection of which our system of exchanging theses 
promises to greatly enrich, its value is stUl greater for special students. 



184 Philosophy. 

Genetic psychology, which one sub-department of this University so 
conspicuously represents, is far larger than the child-study of mothers' 
clubs or teachers' associations. It is simply the entrance of Darwinism 
into the field of mind. Underneath it lies the great transforming concep- 
tion that the soul is as complex, as old, and as gradually unfolded as the 
body, and like it must be studied comparatively in view of all that the 
psychic life of the lower or even the lowest organisms can teach us. 
The new methods cross-section the old classification methods which make 
memory, wiU, perception, imagination, etc., so many faculties, and seek to 
trace the origins of the higher mental powers to their faintest beginnings 
near the dawn of animal life. The most fundamental activities are those 
whose roots extend lowest down in the scale of existence, and these are 
also they that send their tops highest. The conception that mind, as we 
know it in consciousness, has been developed out of something very differ- 
ent that, like organic forms, tends to vary and change indefinitely is a 
new conception and is sure eventually to reconstruct out of new and old 
elements a far larger and more adequate city of Man-soul with reformed 
administrative, educational, religious, and other functions. This move- 
ment appears in biology in the tendency to study psychic phenomena in 
the most rudimentary and microcosmic organisms. It appears again in 
the new and careful studies of instinct in the higher animals, where con- 
ditions can be varied and educational experiments conducted with great 
precaution and detail. Another root of the genetic movement is in the 
anthropology of myth, custom and belief among primitive and savage 
peoples ; another in the studies of degenerative types among the defective 
classes, where decay has inverted the evolutionary order. 

It is on this foundation that the child-study movement rests, and its 
amazing development cannot be adequately explained without a due ap- 
preciation of this wider field. The minute observation and annotation, 
the measuring and weighing of a single child, or the collective study of 
one topic upon the basis of returns from very large numbers of children 
with the help of questionnaires, anthropometric work with its carefully 
wrought out averages, — all this appeals to the instinctive love of children; 
out of it has grown the new conception of childhood as the most generic 
period of life, wherein the limitations of individuality are not yet so pain- 
fully apparent as in adults, and it has given us new conceptions concern- 
ing the nature of genius, the laws of growth, the origin of fear, anger, 
love, the conditions of health, the nascent periods of maximal interest in 



Philosophy. 185 

special lines and topics, until at last education seems likely to have under 
it a far more solid and scientific foundation than it has ever yet attained. 
While this subject has as yet occupied but a slight and recent portion of 
our curriculum, so much has already been accomplished as to warrant the 
very fairest hopes for the future. Among the first results likely to be 
witnessed are the gradual transformation of the methods of teaching and 
of investigating the problems of the special philosophical disciplines some- 
what analogous to the transformation of anatomy and morphology under 
the influence of embryology. How far this movement will extend among 
the other university studies, and whether with or without any new coor- 
dination of the successive stages of individual growth with the historic 
development of different philosophical systems as first presented by Hegel, 
it is impossible to foretell. 



THE LIBRAET. 

By Louis N. Wilson, Librarian. 

From the foundation of the University the library has been consid- 
ered an important factor and has received a great deal of attention 
from the Founder, President, and Faculty. Immediately upon his ap- 
pointment, the President requested each member of the University to 
draw up a list of books in his special field, laying particular stress upon 
important serials and special monographs. These lists were carefully 
collated, duplicates weeded out, and arranged in order for purchase. 
The total number of items amounted in June, 1889, to upward of fifteen 
thousand, a very large proportion being books and journals in foreign 
languages. In order to secure for the University the best possible rates, 
lists of standard works, both in sets and single volumes, were submitted 
for competition to a number of well-known booksellers both in this 
country and in Europe. This necessitated some delay, but it was fully 
warranted by the resultant saving in cost. 

To illustrate this point, the figures submitted by five firms for an 
identical list of 742 items are given here, viz.: 11806.30, $1810.90, 
11971.86, $2038.89, $2166.41, showing a maximum difference of $860.11. 

After carefully comparing all the lists sent in, and taking into con- 
sideration the condition of the books offered, orders were placed with 
firms in New York, Boston, London, Paris, Berlin, Leipzig, and Vienna. 

During the past few years, owing to our very peculiar and constantly 
changing customs and postal regulations, it has become more and more 
desirable to import from Europe through some responsible bookseller in 
this country, in order to avoid the frequent and often vexatious annoy- 
ances consequent upon individual importations. Having decided upon 
a particular bookseller, orders were freely placed with the understanding 
that the library should receive the lowest possible rates consistent with 
good service, and from time to time lists were sent to other firms in order 
to be assured that the agreement was faithfully carried out. A recent 

187 



188 The Library. 

test of this kind showed the following quotations for thirty-five volumes, 
1105.26, $107.57, $120.00. In general, the plan has worked exceedingly 
well. 

During the summer of 1889, while these orders were being executed, 
Mr. Clark placed the first books in the library by donating about thirty- 
two hundred volumes. A large proportion of these, on history, biogra- 
phy and travel, were given with the original bookcases as they had 
stood in his own private library. Another part of the collection con- 
sisted of the following sets of bound periodicals, almost all complete 
down to the end of 1883 : Atlantic Monthly, Blackwood's Magazine, Cen- 
tury Magazine, Cornhill Magazine, Edinhurgli Mevie^v, Fortnightly Review, 
G-entleman' s Magazine, Harper's Magazine, LittelVs Living Age, Macmillan's 
Magazine, North American Review, North Bintish Review, Notes and 
Quei'ies, Popular Science Monthly, PutnanCs Magazine, Quarterly Review, 
and Scribner's Monthly, also a set of the Report on the Scientific Results 
of the Voyage of H. M. S. Challenger, during the years 1872-76. Yet a 
third part consisted of a large number of rare old books, some of which 
are fine examples of early printing when there was no title-page, no 
pagination, date, or printer's name, and where the initial letters were 
omitted to be inserted later by hand. Of these fine old volumes, the 
following are mentioned as examples : — 

Paulus de Sancta Maria Scrutinimn scripturarum. Probably the oldest book 

in our library, with no title-page, colophon, pagination, or signatures. 

Rubricated throughout. 
Rationale divinorum officiorum. Supposed to have been printed at Basle in 

1474-75. 
Astexanis Suma. Libri VIII., de preceptis, de virtutibus et viciis; de sacra- 

mentis de sacro penitentie, de Sacramento ordinis, de excommunicatione ; de 

niatrimonio. Venetiis, 1478. 
Roberti Caraczoli de Licio de timore divinorum judiciorum ac de morte. 

Nuremberge, 1479. 
Albert! de Padua expositio Evangeliorum dominicalium totius anni et concor- 

daucia quatuor evangelistarum in passionem domiuicam a Mcolao Vinckel- 

spickel. Ulm, 1480. 
Sancti Thome de Aquino ordinis predicatorum super quarto libro sententiarum 

preclarum opus. Venetiis, 1481. 
Liber moralitatura elegantissimus magnarum rerum naturalium lumen anime 

dictus. 1482. 
Sancti Hieronimi Vitee Patrum Sanctorum Egiptiorum. Niirnberg (Koburger) 

1483. 



The Library. 189 

Blondi Flavii historiarum ab inclinatione Eomanonun Imperii, libri XI. 
Venetiis per Octavianum Scotum. 1483. 

Johannis de Turrecremata questionum dignissimarum cum solutionibus earum- 
den, etc. Davantriss, 1484. A work of the celebrated Spanish Dominican 
Juan de Torquemada. 

Legende de saneti composte per Jacobo de Voragine. Venetia, 1484. 

An old German almanac beautifully printed in red and black and pasted on 
one of the covers of Hieronimi Vitm Patrum. It runs from 1486 to 1679, 
and was probably printed at the earlier date. 

Summa Rainerij de Pisis. Venetiis, 1486. 

Liber Cronicarum cum figuris et imaginibus ab initio mundi usque nunc tem- 
poris Impressum ac finitum in vigilia purificatiouis Marie in imperiali 
urbe Augusta a Johanne Schensperger. Anno ab incarnatione domini 1497. 
The so-called Nuremberg Chronicle, with numerous woodcuts by Wolge- 
muth, the master of Albrecht Dtirer. 

Sermones Pomerii de Tempore Hyemales et Estivales et sermones quadragesi- 
males per Helbartum de Themeswar. Hagenaw, 1602. With rubricated 
initials. 

Pauli Jovii elogia virorum bellica virtute illustrium veris imaginibus supposita, 
quae apud Musseum spectantur. Florentise, 1551. 

Kamusio, Primo volume, & Terza edizione delle navigationi et viaggi. Vene- 
tia, Giunti, 1563. The first volume of Ramusio's well-known collection of 
voyages and travels, containing among other things Pigafetta's log during 
the first voyage around the world under Magalliaes. 

Missale Eomanum, ex Decreto Sacrosancti Concilii Tridentini restitutum, Pii V. 
Pont. Max. jussu editum. Venetiis, apud Juntas, 1602. 

The Bible : that is the Holy Scriptures contained in the Old and New Testa- 
ment. London, 1610. A copy of the so-called Breeches Bible. 

Missale Eomanum, ex Decreto Sacrosancti concilii Tridentini restitutum, Pii V. 
Pont. Max. jussu editum et dementis VIII. auetoritate recognitum. Ingol. 
stadii, 1610. 

Montanus (Arnoldus) De Nieuwe en Onbekende Weereld of Beschryving van 
America. Amsterdam, 1671. An old description of America in Dutch. 

Esquemeling (John) and Eingrose (Basil), History of the Bucaniers of America. 
London, 1695. Esquemeling, who spent many years at Tortuga, gives here 
a very graphic account of the buccaneers. 

Armenian Bible. Venice, 1805. Fleeing from the persecution of their ortho- 
dox brethren, the Catholic Armenians of the mechitaristic order established 
themselves at the island of San Lazzaro, granted them by the Eepublic of 
Venice. Many a learned volume issued from their press, of which this is 
a specimen. 

New Testament in Lettish language. Mitau, 1816. 

Select Fables ; with cuts, designed and engraved by Thomas and John Bewick, 
previous to the year 1784 ; together with a Memoir and a descriptive cata^ 



190 The Library. 

logue of the works of Messrs. Bewick. Newcastle, 1820. Thomas Bewick 
is considered the restorer of wood engraving in England. 
Cookson (Mrs. James). Flowers drawn and painted after nature in India. 
1834. 

In addition to a number of books presented to the library by Presi- 
dent Hall, we are indebted for gifts to the following citizens of Worces- 
ter : Hon. George F. Hoar, Mr. Henry J. Howland, Hon. Henry L. 
Parker, Mr. Samuel H. Putnam,^ the late Hon. W. W. Rice, Hon. 
Stephen Salisbury, Hon. John D. Washburn, and Hon. John E. Russell 
of Leicester. 

To receive the books temporary wooden stacks were erected in the 
main library room, and so substantially were they constructed that they 
are still serviceable. Solid oak shelving was put up on both sides of the 
reading-rooiu, adjoining the main library room, with a three-foot pro- 
jecting shelf three and a half feet from the floor, upon which the current 
numbers of periodicals are displaj'^ed. 

To the problem of cataloguing and classification, always a difficult one, 
both the President and the members of the Faculty gave a good deal of 
time and attention. It was felt that the scheme of classification must not 
be too rigid, and that nothing should be allowed to interfere with the free 
use of the books by all members of the University. The books were first 
carefully classified upon the shelves by departments, and marked as 
follows : — • 

A. Works of GEiiTEEAL Eefeeence. I. Psychology. 

B. JouEisTALS. J. Philosophy. 

C. Mathematics. K. Ethics. 

D. Physics. L. Criminology. 

E. Chemistry. M. Anthropology. 

F. Zoology. N. Education. 

G. Physiology. 0. Botany. 
H. Pathology. 

The various subdivisions in each department may be inferred from 
that of the mathematical department. 

lA copy of "Justini historici clarissimi in Trogi Pompeii historias Libri XLIIIV 
Venice, Jenson. 1470. Duke de Noailles' copy of the e(ZiJio pj-i'nceps. " Virorum Illustrium 
vit(B ex Plutarcho Grceco in Latinum Versce Solertiqae, cura emendata: fceliciter expliciHt : "per 
Nicolaum Jensen Gallicum Venetiis Ipressoe. 1478, die. II Jannarii. 2 vols. "The 
Scientific Papers of James Clerk Maxwell." Edited by W. D. Kiven, P. B. S. The Univer- 
sity Press, Cambridge, 1890. 2 vols. 



The Library. 



191 



C. — Mathematics. 

In Mathematics, C, the books are grouped in ten divisions, designated 
by the numerals 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, immediately following the let- 
ter C ; every division is subdivided into sections of which each is desig- 
nated by a second numeral following that indicating the division. The 
cipher, 0, always denotes a miscellaneous division or section. The math- 
ematical works are arranged on the shelves in accordance with the fol- 
lowing classification, the subdivisions of which, however, are not all used 
at present. The italicized part of each title is that printed on the sliding 
shelf label. 



C 1. History and Philosophy. 
C 1. 1. Bibliography. 
CI. 2. History. 
C 1. 3. Biography. 
C 1. 4. Philosophy. 

C 2. Collections. 

C 2. 1. Works, complete and select. 
C 2. 2. Compendia, Dictionaries. 
C 2. 3. Tables. Formulae. 

C 3. Symbolism and Opeeation. 
C 3. 1. Symbolic Methods. 
C 3. 2. Operations. 
C 3. 3. Multiple Algebra (ref. C 9). 
C 3. 4. Symbolic Logic. 
C 3. 0. Miscellaneous Symbols. 



C 4. Arithmetic. 


C4. 1. 


Elementary Arithmetic. 


C4. 2. 


Continued Fractions. 


C4. 3. 


Numericcd Series. 


C4. 4. 


Finite Differences and Sum- 




mation. 


C4. 5. 


Permutations and Combinor 




tions. 


C4. 6. 


Probabilities. 


C4. 7. 


Theory of Numbers. 



C5. Algebka. (For Multiple Alge- 
bra see C 3. 3.) 
C 5. 1. Elementary Algebra. 
C 5. 2. Determinants. 



C 5. 3. TJieory of Equations. 

C 5. 4. Simultaneous Equations. 

C 5. 5. Transformation. 

C 5. 6. Invariants. 

C6. Infinitesimal Calculus. 

C 6. 1. Limits and Infinite Series. 

C 6. 2. Functions of a Heal Varia- 
ble. 

C 6. 3. Differential Calcidus. 

C 6. 4. Integral Calculus. 

C 6. 5. Total Deferential Equations. 

C 6. 6. Partial Diffeiential Equor 
tions. 

C 6. 7. Functions Derived from 
Differential Equations. 
Spherical Harmonics. 

C 6. 8. Calculus of Variations. 

C 7. Theory of Functions. 

C 7. 1. General TJieory. 

C 7. 2. Algebraic Functions. 

C 7. 3. Exponential and Trigono- 
metric Functions. 

C 7. 4. Elliptic Functions and In- 
tegrals. 

C 7. 5. Hyperelliptic and Abelian 
Functions and Integrals. 

C 7. 6. Various Functions (fuch- 
siennes, etc.). 

C 7. 7. Functions of Several Varia- 
bles. 



192 



The Library. 



C 8. Geometry. 

C 8. 1. Elementary Geometry and 
Trigonometry. 

C 8. 2. Analysis Sitits. 

C 8. 3. Analytic Geometry in Gen- 
eral. 

C 8. 4. Projective Geometry. Mod- 
ern Synthetic Geometry. 

C 8. 5. Special Systems of Geomet- 
ric Analysis. 

C 8. 6. Plane Loci in particular. 

C 8. 7. Loci in 3 Dimensions in par- 
ticular. 

C 8. 8. Hyperspace and Non-Eucli- 
dean Geometry. 

C 8. 9. Applications of Geometry. 



C 9. Extensive Algebea (ref. C 3. 3). 

C 9. 1. Geometric Representation of 
the Imaginary. 

C 9. 2. Quaternions. 

C 9. 3. Geometric Algebras (Clif- 
ford). 

C 9. 4. Ausdehnungslehre (Grass- 
mann). 

C 9. 5. Equipollences (Bellavitis). 

CO. Miscellaneous. 
C 0. 1. Apparatus. 
C 0. 2. Recreations, Games, Puzzles, 

etc. 
C 0. 9. Paradoxes and Paradoxers. 

Circle-squaring, etc. 



As B is the general designation of periodicals, each periodical exclu- 
sively devoted to one department is designated by B, followed by the 
letter of the department to which it belongs, thus : 

B C. Mathematical Periodicals. 

B A. Miscellaneous Periodicals. Transactions of learned societies, etc. 

So long as the number of books in any section is vevj small, they are 
grouped under the division to which that section belongs, and are desig- 
nated only by the number of that division. All books which refer to 
several divisions are placed in the division C 2 (collections), and all 
books referring to several sections of any one division are grouped under 
that division, unless they refer but slightly to more than one division or 
section. Volumes of a set are not separated, but the whole set is classed 
as if it were a single volume. Otherwise, every book is placed in the 
narrowest division or section to which it belongs. 

The library has two card catalogues : — 

I. An author's catalogue arranged alphabetically with miscellaneous 
and anonymous sections, so that nearly all books in the library are 
represented in it. 

II. A subject catalogue which is at the same time a shelf and an 
inventory catalogue. This is arranged as follows : Every volume and 
every pamphlet has its card, so that each card represents a volume. 
All the books are classified and arranged upon the shelves according to 
the departments, divisions, and subdivisions, but under each subdivision 



The Library. 193 

books are placed alphabetically by authors. While each case, tier, and 
shelf is permanently labelled, the demarcation between the subdivisions is 
made by sliding shelf label holders bearing the subject, division, and sub- 
division. These label holders being movable, the subdivisions can easily 
be enlarged as new books are added. 

In mathematics, for instance, C 1, history and philosophy, comes first, 
with the first subdivision, CI, 1, bibliography. First on the top shelf, 
and therefore first in the catalogue drawer set apart for these tiers, 
comes bibliography, beginning with authors in A, and so on through the 
alphabet to the end of the subject. Then come history, biography, etc., 
on through mathematics and the other departments, the order of cards 
being identical with the order of the books upon the shelves, reading 
down the tiers as down a printed page. 

In the drawers the book cards are separated by red cards projecting 
on the right above the others, and on these projections the tier and shelf 
divisions are marked ; they are also separated by blue cards projecting 
above the others on the left-hand side, on which the subjects are marked. 
Whenever the position of any book is changed, it is only necessary to 
make a corresponding change in the position of its card. The shelf posi- 
tion of each book is marked in pencil, not upon these cards, but upon 
each card in the author's catalogue, and in the book itself, in order that it 
may be readily found and replaced. 

New books, after being entered in the author's catalogue, are kept in a 
case reserved for them for a few weeks before being permanently placed 
on the shelves and entered in the inventory catalogue. 

A full list of all serial publications taken by the library is kept in a 
special drawer of the catalogue case, so that a person unfamiliar with the 
library may ascertain, with very little trouble, what periodical publications 
are to be found here. 

Worcester is fortunate in possessing an excellent Public Library of 
more than 120,000 volumes, and well supplied with serial publications. 
In the early years of the University, it was the hope of the Founder that 
we might confine our purchases to such books and journals as were not to 
be found in the Public Library, and that the two might supplement each 
other ; this plan was largely carried out in the earlier years, but later the 
needs of our students demonstrated the necessity of the duplication of 
the more important scientific publications, though we still depend upon 
the Public Library for works of a less special character, and our students 



194 The Library. 

have availed themselves of the library privileges thus extended to them 
to the fullest extent. 

Besides its indebtedness to the Worcester Public Library the Uni- 
versity is under great obligations to the following for frequent loans : 
Library of the Surgeon-General's Office, Washington, D.C. ; Library of 
Harvard University ; The City Library Association of Springfield, Mass. ; 
Boston Public Library ; Public Library, Cleveland, Ohio ; Trinity College 
Library and Case Memorial Library, of Hartford, Conn. ; Library of Yale 
University ; Forbes Library, Northampton, Mass. ; Library of Vassar 
College ; and many others. Several of these libraries have freely lent us 
books and volumes of serial publications, often of the greatest importance 
to those engaged in research work. No library, however large, can hope 
or expect to be prepared to meet all the calls upon it, and a glance at 
the diverse and advanced character of the publications issued from this 
University ^ shows how varied and numerous are the demands upon this 
department. 

To the Library of the American Antiquarian Society we are especially 
indebted for the kindly spirit of cooperation invariably shown. While 
strictly a reference library, its officers have ever been ready and willing to 
make reasonable exceptions in aid of the cause of historical and scientific 
research. 

The library is a veritable laboratory, and is looked upon as a work- 
room, and not as a museum with contents too sacred to be profaned by 
use. It is a favorite meeting-place for professors and students, where 
the heads of departments meet their men to direct their reading and 
demonstrate to them how to make the best use of a well-selected collection 
of scientific books. The books are readily accessible to every member of 
the University, and there is no limit to the number that may be taken 
out. Each one enters the volumes he takes out upon a printed form pro- 
vided for that purpose ; if not returned at the end of ten days, they are 
renewed by the librarian for another period of ten days, at which time 
they must be returned, but may be taken out again upon the following day. 

The library is open to all persons outside the University who are 
interested in any of its lines, and its books are freely lent to such persons, 
who are thus placed for the time being upon the same footing as mem- 
bers of the University ; and, while we borrow during term time an aver- 
age of fifty volumes a month, we lend as freely. The library is rich in 

1 See Bibliography at the end of this volume. 



The Library. 195 

certain special lines, and is often used by experts from other universities, 
state and national institutions. 

President Hall has an exceptionally fine private library, especially rich 
in pamphlets and special monographs in the various fields of philosophy, 
psychology, and education. During these ten years all students have 
been permitted to draw upon it as freely as upon the University library, 
and the eflSciency of this department has been largely due to Dr. Hall's 
broad-minded and liberal conception of the function of the printed vol- 
ume. In his various courses he frequently gives demonstrations of books, 
pointing out the best books in each subject, the best to buy, the best to 
read, emphasizing and explaining the strong points in each, etc. 

In spite of the absolute freedom of the library, the loss of books has 
been surprisingly small. Once a year the books are carefully checked by 
means of the shelf cards, and in very few years have the losses amounted 
to more than two or three volumes. The missing volumes one year fre- 
quently turn up later, so that a careful estimate recently made shows the 
actual money value of the books lost in ten years to be less than fifty 
dollars. 



Almost all who are interested in libraries have ideals as to the future 
development of their special fields, and the librarian has attempted, in the 
course of the past ten years, to formulate an ideal of an university library. 
He alone is responsible for his views, and is encouraged to state them here 
by the fact that the President and Faculty have given him the greatest 
freedom and their warmest support in all matters pertaining to his de- 
partment. 

The ideal library should be housed in its own building, and not rele- 
gated to rooms in a building constructed for other purposes. In con- 
structing such a building, the chief end in view should be to provide 
every facility for the use of books, and this end should never be sacrificed 
for architectural features or artistic purposes. Each department in the 
University should have a working library in its own rooms, but whatever 
books are placed in these department libraries should be duplicated in the 
main library. The building should be large enough to allow the book 
shelves to be arranged around the rooms, leaving the greatest amount of 
open space in the centre. Movable working desks, liberally supplied with 



196 The Library. 

conveniences for writing, and containing ample drawer space for note-books 
and papers, are miicli to be preferred to the large fixed tables usually 
found in library buildings. The shelving should be of the most approved 
modern type, insuring economy of space and the proper care of the books, 
and the highest shelf within easy reach from the floor. The rooms should 
be provided with every possible convenience, including a sufficient num- 
ber of comfortable chairs, with cozy nooks and corners inviting to a quiet 
half -hour with a book, when one would otherwise be disinclined to read. 
That the light should be good, the ventilation absolutely perfect, and the 
attendants have but one purpose — the service of the readers — are obvi- 
ous essentials. 

In these days of rapid multiplication of new libraries and enlargement 
of many older ones, there is a great demand for complete sets of serial 
publications, and many of the important journals are growing rapidly 
scarce and difficult to obtain. It is, therefore, particularly desirable in an 
institution of this character to procure, as soon as possible, full sets of all 
the serial publications in its various departments and on all allied subjects, 
and every effort should be made, and no expense spared, to procure all the 
scientific contributions by specialists in the work represented here, or in 
departments likely to be of service in research work. 

The current numbers of all these publications should be placed before 
the members of the University promptly, as it is imperative that those 
engaged in original investigation be advised of the latest literature on the 
subject, or of the work others are doing along similar lines. 

A most important part of a good library is its catalogue. The day 
has gone by when men can afford to spend hours in hunting among a mass 
of books to ascertain what the library possesses upon a given subject, or 
to rely upon the memory of the librarian and attendants, be thej'' ever so 
erudite. While, therefore, the aim should be to keep in printed and card 
form a list of all the books and articles that have been written upon a 
given subject, nothing should be allowed to interfere with the prompt 
cataloguing under subject headings of everything that the library pos- 
sesses. Two questions always arise here, first, " Where can I find a list 
of all printed matter upon my subject ? " and secondly, " How much of 
that printed matter is to be found in this library ? " A complete card 
catalogue can be so arranged as to answer perfectly these two questions. 

In this, as in every well-regulated library, printed forms should be 
provided to encourage readers to make suggestions and complaints to the 



The Library. 197 

library committee ; the latter, in no case, to pass through the hands of 
the librarian. 

The subject of binding is always an important one, and we feel very 
keenly the need of united action on the part of all the libraries of the city 
in this respect. A carefiil inquiry has developed the fact that between 
14000 and $5000 is expended yearly by the various institutions in this 
city for this purpose. There are unmistakable signs that the art of book- 
binding, which has for ages commanded the services of eminent crafts- 
men, as well as of men and women eminent in art, is receiving increased 
attention from book lovers here, and the time may not be far distant when 
this question will be taken up by a committee representing the different 
libraries. 

There would seem to be no reason also why the various institutions 
should not, in the near future, devise a system of cooperation, as is already 
proposed in Toronto, by means of which the resources of all the libraries 
in the city could be drawn upon by each. 



EEPORT OF THE TREASURER. 

At the first meeting of tiie Trustees of Clark University, May 4, 1887, 
Mr. Clark proposed to give : — 

(1) " The sum of $300,000 (payable as the same shall be needed) to the Gen- 

eral Working or Construction Fund to be applied in the erection of 
buildings and equipping them with such appliances and facilities as 
may be deemed necessary for putting the University in good working 
order." 

(2) " The sum of $100,000, the income of -which shall be devoted to the support 

and maintenance of a University Library." 

(3) " The Sinn of $600,000, the income of which is to be devoted to the general 

uses of the University in its support and management, and which 
for the sake of convenience may be called the University Endowment 
Fund." 
"The Library and the Endowment Funds are never to be diminished, and 
no part of the principal is in any event ever to be applied to the objects 
to which the income of each is to be devoted. If by any accident or 
loss, either of said funds shall at any time become impaired, then the 
income of each of said funds shall be added to the principal until such 
impairment is made good and the funds restored to their original 
amounts." 

In addition to the foregoing gifts, Mr. Clark then and subsequently 
conveyed to the Trustees of the University, real estate, the valuation of 
which on the books of the assessors of the city of Worcester is $135,600. 

In the Treasurer's Annual Statement for the year ending August 31, 
1899, which follows, is an account of the Library and University Endow- 
ment Funds. 

The amounts expended for construction and equipment of buildings 
under the terms of Mr. Clark's first proposal have been as follows : — 

199 



200 



Report of 



Construction of the Main University Building . . $159,780.60 

Construction of the Chemical Laboratory . . . 66,131.94 

Equipment of the Maia Building 18,480.28 

Equipment of the Chemical Laboratory .... 14,801.47 

Apparatus and Supplies 29,082.73 

$278,277.02 
Additional land was purchased by Mr. Clark for the 

University at an expense of $12,233.04 

The balance to make up the proposed $300,000 . . 9,489.94 
was subsequently expended in the additional equip- 
ment of the different departments. 



A statement of the expenses of the several departments for the years 
1890-98, inclusive, including the amounts expended in the original equip- 
ment above mentioned, is appended. 









1890. 


1891. 


1892. 


1893. 


1894. 


Mathematics . 
Physics . . . 
Chemistry . . 






1 6,664.49 

17,214.20 

25,334.24 

28,083.29 

. 13,604.17 

750.00 

15,568.04 

5,829.00 

9,067.43 

3,860.00 


$ 7,235.00 
7,320.98 
7,491.00 
15,429.70 
11,400.00 
1,550.00 
5,733.41 
2,900.00 
5,162.92 
4,560.00 


$ 7,356.50 
6,768.46 
6,298.46 
12,732.58 
7,059.16 
1,151.25 
1,279.84 
3,000.00 
4,183.77 
7,240.00 


$ 6,926.40 
3,567.78 
2,693.26 
3,676.47 
7,666.03 
1,586.13 
1,334.45 
3,800.00 
8,983.01 
5,280.00 


$ 5,905.64 
2,330.30 
1,337.64 
2,066.20 


Psychology . 
Education . . 




6,584.00 
1,826.87 
2,596.33 


Administration 
Expense . . 
Fellowships . 




2,600.00 
3,773.51 
4,980.00 








$125,974.86 


$68,783.01 


$57,070.02 


$45,513.53 


$34,000.49 



Mathematics . 

Physics . . . 

Biology . . . 

Psychology . . 

Education . . 

Library . . . 
Administration 

Expense . . . 
Fellowships 



1895. 



5,900.00 
2,329.07 
2,072.74 
6,015.46 
1,312.29 
1,628.72 
2,600.00 
3,434.13 
4,740.00 



$ 5,900.00 
2,393.03 
2,200.00 
7,010.00 
1,250.00 
1,740.16 
2,600.00 
4,319.80 
4,620.00 



,032.41 $.32,032.9 



1897. 



I 5,900.00 
2,948.73 
2,300.00 
7,010.00 
1,250.00 
2,456.00 
2,600.00 
4,237.82 
3,420.00 



2,122.55 



1898. 



5,900.00 
2,173.00 
2,054.24 
6,676.33 
1,250.00 
3,.508.48 
2,600.00 
3,190.93 
1,500.00 



$28,852.98 



the Treasurer. 201 

In addition to the endowment and gifts, which have already been 
referred to, Mr. Clark has given to the University for its general 
purposes : — 

1889-90 fl2,000 

1890-91 50,000 

1891-92 26,000 

1892-93 18,000 

$106,000 

The University has received from Mrs. Eliza W. Field "a fund of 
1500 to be called the John White Field Fund, the income of which is to 
provide for the minor needs of a Scholar or Fellow." 

There was also presented to the Trustees of the University by Hon. 
George S. Barton of Worcester $5000, the income of which is to be 
devoted to the aid of " some one or more worthy native born citizens of 
the city of Worcester, who may desire to avail themselves of the advan- 
tages of the institution." 

Hon. Henry L. Parker, in the summer of 1892, in behalf of many 
citizens of Worcester, presented the University with a tower clock and 
the sum of $781.30 to provide for its maintenance, which fund is known 
as the Clock Fund. 



KEPORT OF THE TREASURER TO THE TRUSTEES FOR THE YEAR 
ENDING AUGUST 31, 1899. 

To THE Trustees op Clark University, 

Grentlemen, — I have the honor to submit herewith my annual report 
for the year ending August 31, 1899. 

The total receipts of the University from Sept. 1, 1898 to Aug. 31, 1899, 

inclusive, were .... $48,595.63 

The total disbursements during the same period were . . . 37,130.27 
Leaving a balance on hand Sept. 1, 1899, of $11,466.26 



202 Report of 

(A.) 

The items of income are as follows : — 

Gross Income of the "University Endowment Fund .... $28,407.33 

Gross Income of the Library Fund 5,258.46 

Gross Income of the University 1,586.00 

Gross Income of the Summer School, 1899 1,388.50 

Subscriptions to the Fund for the Decennial Celebration . . 4,150.00 

From the Field Fund 20.00 

Balance from previous year 7,785.24 

Total $48,595.63 

(B.) 

The expenditures have been as follows : — 

For the Department of Mathematics f 6,300.00 

For the Department of Physics 2,641.11 

For the Department of Biology 2,012.25 

For the Department of Psychology 7,966.82 

For the Department of Education 1,250.00 

Administration 2,700.00 

Expense 4,729.87 

Field Scholarship 20.00 

Expenses of Summer School 889.85 

Expenses of the Decennial Celebration 3,156.85 

Library Expenses 3,474.08 

Sinking Fund 700.00 

Jonas G. Clark on account of premiums 900.00 

Accrued interest repaid 389.44 

$37,130.27 
(C.) 

The incidental earnings of the University from fees, etc., were . $ 1,586.00 

p.) 

Account of the Summer School for 1899 : — 

Eeceipts f 1,388.50 

Expenses 889.85 

Balance carried to University Account $ 498.65 

(E.) 

Subscriptions to the Decennial Celebration : — 

Eeceipts $ 4,150.00 

Expenses 3,156.85 

Balance on hand appropriated to the publication of this volume . $ 993.15 



the Treasurer. 



203 



6s, 



R., 1st Consol, 



(F.) 

The University Endowment Fund is invested as follows : — 



Oregon Eailway and Navigation Co., 4s . 

West Shore R. R. Co., 1st Mtg., 4s, 2361 . 

City of Cambridge, Sewer Loan, 6s, 1905 . 

Norwich and Worcester E. R. Co., 4s, 1927 

Rutland E. R., 1st Mtg., 6s, 1902 . 

Wilkesbarre and Eastern E. E., 1st Mtg., 
1942 

Hereford Ey. Co., 4s, 1930 

Chicago and Eastern Illinois R 
Mtg., 6s, 1934 
1st Mtg. Sink. F., 6s, 1907 

Wayne Co., Michigan, 4s . 

Northern Ohio Ry. Co., 1st Mtg., 5s 

Lowell, Lawrence, and Haverhill St. Ey., 1st 
Mtg., 5s 

Worcester and Suburban St. Ry., 1st Mtg., 5s 

Worcester and Marlboro St. Ry., 1st Mtg., 5s 

Atchison, Topeka and Santa Fe Ry. Co., . 
Gen. Mtg., 4s . . . $18,500.00 
Adj., 4s .... 10,000.00 

Certif. Gen. Mtg., 4s . . 250.00 

Second Ave. E. E. Co., New York, 1st Consol, 
Mtg., 5s, 1948 .... 

15 shares Worcester National Bank 

71 shares Norwich and Worcester E. E. . 

Deposit in Worcester Co. Inst, for Savings 

Deposit in Five Cents Savings Bank 

100 shares Fitchburg (preferred) 

35 shares New York, New Haven, and Hart- 
ford E. E 

100 shares Worcester Traction Co. (preferred) 

New England Yarn Co., 6s . . . 

Lake Shore Collaterals, 3^s 

Invested in premiums .... 

Cash in Worcester National Bank 



Book value. 


Market value. 




Sept. 1, 1899. 


$110,000.00 


$112,750.00 


75,000.00 


84,750.00 


20,000.00 


22,600.00 


75,000.00 


84,000.00 


25,000.00 


26,600.00 


9,800.00 


10,600.00 


9,350.00 


10,000.00 


10.000.00 


13,700.00 


1,000.00 


1,145.00 


30,000.00 


31,200.00 


3,000.00 


3,180.00 


16,000.00 


15,760.00 


6,000.00 


6,240.00 


10,000.00 


10,400.00 


25,000.00 






18,500.00 




8,800.00 




250.00 


26,000.00 


30,000.00 


2,260.00 


2,700.00 


14,603.60 


15,620.00 


5,000.00 


5,000.00 


10,000.00 


10,000.00 


10,300.00 


11,800.00 


6,982.50 


7,630.00 


10,700.00 


10,450.00 


11,000.00 


11,495.00 


60,000,00 


50,000.00 


16,230.00 




28,920.26 


28,920.25 


$614,136.25 


$634,480.25 



204 



Report of 



The gross income of the University Endowment 
Fund was 



There was paid from this : — 

To Sinking Tund to provide for premiums . . . $700.00 
To Jonas G. Clark on account of premiums . . 900.00 

Accrued interest repaid 389.44 

Leaving net income carried to University Account 



$28,407.33 



$1,989.44 



3,417.; 



(G.) 

The Library Fund is invested as follows : — 



50 shares Washington National Bank, Boston 
25 shares Tremont National Bank, Boston . 
50 shares Merchants' National Bank, Boston 
50 shares National Bank of Republic, Boston 
50 shares Union National Bank, Boston 
50 shares Second National Bank, Boston . 
50 shares New England National Bank, Boston 
50 shares Atlas National Bank, Boston. 
61 shares State National Bank, Boston 
15 shares Suffolk National Bank, Boston . 
50 shares Eliot National Bank, Boston 
50 shares National Bank of Commerce, Boston 
50 shares Boylston National Bank, Boston 
43 shares Old Boston National Bank, Boston 
10 shares City National Bank, Worcester . 
15 shares Norwich and Worcester R. R. stock 
Northern Ohio R. R. Bonds, 5s . 
15 shares New York, New Haven, and Hartford 

R. R 

Invested in premiums .... 

Deposit in Worcester National Bank . 



The gross income of the Library Fund was 

From dividends and interest .... 

Rebate on bank tax, 

Balance carried to Library Expense Account 



Book value. 


Market value. 




Sept. 1, 1899. 


$ 5,527.00 


$ 6,000.00 


1,766.00 


(in liquidation) 


7,934.60 


8,600.00 


7,994.88 


8,750.00 


6,829.50 


7,150.00 


9,162.50 


8,850.00 


8,237.50 


7,825.00 


6,293.50 


5,750.00 


6,938.01 


7,167.50 


1,527.21 


1,650.00 


6,598.00 


7,150.00 


6,552.62 


6,625.00 


6,530.75 


6,860.00 


4,527.63 


6,074.00 


1,500.00 


1,600.00 


3,000.00 


3,300.00 


4,000.00 


4,240.00 


2,992.50 


3,270.00 


150.00 




2,273.05 


2,273.05 


$99,335.25 


$100,024.55 




$4,085.77 




1,172.67 



$5,268.44 



the Treasurer. 205 

(H.) 

The Library Expense Account : — 

Unexpended balance from previous years . . . $3,091.18 

Credits for books sold 412.38 

Income of the Library Fund for 1899 .... 5,258.46 f 8,762.02 
The expenses, including $900 for administration, heat 

and light, were 3,886.46 

Leaving a balance Sept. 1, 1899, of . . . $4,875.66 

The George S. Barton Fund, deposited in the Worces- 
ter Co. Inst, for Savings, amounts to . . $7,239.24 
Income during the year 278.43 

(J.) 

The John White Field Fund, deposited in the Worces- 
ter Co. Inst, for Savings, amounts to . . . $653.22 
Income during the year 25.74 

(K.) 

The Clock Fund, deposited in the Five Cents Savings 

Bank, amounts to $878.40 

Income during the year 33.93 

(L.) 

The Sinking Fund, to provide for premiums, is de- 
posited in the Worcester Five Cents Savings 
Bank, and amounts to $2,670.42 

(M.) 
The salaries of the University Faculty were . . $19,990.00 

(N.) 
Fellowships and Scholarships $1,310.00 

(0.) 
Salaries of employees $2,135.00 

Apparatus and supplies $870.18 

Respectfully submitted, 

Thomas H. Gage, Treasurer. 



206 Report of the Treasurer. 

We have examined the books and accounts and securities of Clark 
University, and find them to be correct and as stated in the foregoing 
treasurer's report for the year ending August 31, 1899. 

James P. Hamilton, 
T. H. Gage, Jb., 

Auditors. 



LECTUKES ON MATHEMATICS. 

By Professor Emile Picaed. 

Premieeb Coitfbrence. 

Sur rUxtension de quelques Notions MatJiematiques, et en particulier de 
VIdee de Fonetion depuis un Siecle. 

Mes premiers mots seront pour adresser mes remerciments au Gonseil 
de cette Universite qui m'a fait Thonneur de m'inviter a ces fetes et m'a 
charge de prendre la parole devant quelques mathematiciens americains. 
C'est un hoimeur auquel je suis tres sensible, car nous savons en France 
que las etudes mathematiques se developpent rapidement en Amerique 
et nous suivons ce mouvement avec une tres vive sympathie. Votre 
American Journal of Mathematics compte parmi les journaux periodiques 
les plus importants et renferme de remarquables memoires, et je lis 
toujours pour ma part avec grand profit et interet le Bulletin de la 
Societe mathematique americaine, excellente reviie historique et critique 
qui tient ses lecteurs au courant des travaus les plus recents. J'ai 
appris aussi que cette Societe allait fonder un nouveau recueU destine 
a des memoires plus etendus ; je ne doute pas qu'il ne soit appele a un 
brillant avenir. Dans les trois causeries que nous allons avoir ensemble, 
je ne puis songer a aborder un sujet special qui demanderait une pre- 
paration particuliere. Nous allons rester dans les generalites et jeter un 
rapide coup d'csil sur 1' extension de quelques notions mathematiques et 
en particulier, de I'idee de fonetion depuis un siecle. 

I. 

Toute la science mathematique repose sur I'idee de fonetion c'est a 
dire de dependance entre deux ou plusieurs grandeurs, dont I'etude con- 
stitue le principal objet de I'analjse. II a fallu longtemps avant qu'on 
se rendit compte de I'etendue extraordinaire de cette notion ; c'est la 
d'ailleurs une circonstance qui a ete tres heureuse pour les progres de la 
Science. Si Newton et Leibnitz avaient pense que les fonctions continues 
n'ont pas necessairement une derivee, ce qui est le cas general, le calcul 

207 



208 Emile Picard: 

differentiel n'aurait pas pris naissance ; de meme les idees inexactes de 
Lagrange sur la possibilite des developpements en series de Taylor ont 
rendu d'immenses services. Sans vouloir trop generaliser, on pent dire 
que I'erreur est quelquefois utile, et que, dans les epoques vraiment 
creatrices, une verite incomplete ou approchee peut etre plus feconde que 
la meme verite accompagnee des restrictions necessaires ; I'liistoire de la 
science confirme plus d'une f ois cette remarque et, pour rappeler encore 
Newton, il est heureux qu'il ait eu au debut de ses recherches pleine 
confiance dans les lois de Kepler. Les geometres du siecle dernier, sans 
remonter plus haut, ne raffinaient pas sur I'idee de fonction; pour eux, 
une fonction d'une variable est une fonction qu'on peut representer par 
une courbe formant un trait continu ; ce sont ces fonctions qu'Euler 
appelait functiones continuce. La question de la representation d'une 
fonction arbitraire sous une forme analytique dans laquelle interviennent 
seulement les operations fondamentales de I'aritlimetique effectuees un 
nombre fini ou infini de fois, se posa, semble-t-il pour la premiere fois 
a propos du probleme des cordes vibrantes. D'Alembert avait donne 
I'integrale de I'equation 

sous la forme f(^x + at^ + ^(z — at'). Daniel Bernoulli montra qu'on 
pouvait satisfaire a I'equation differentielle et aux conditions aux limites 
par une serie trigonometrique, et il affirma que cette serie donnait la 
solution la plus generale. Ce fut I'occasion d'une longue discussion entre 
Bernoulli, Euler et Lagrange. Pour ces grands geometres, une fonction 
arbitraire etait toujours la fonction arbitraire susceptible d'etre repre- 
sentee par un trait continu. En 1807, dans un memoire celebre, et, plus 
tard, dans sa theorie analytique de la chaleur, Fourier montra I'extreme 
importance des series trigonometriques ; il a, le premier, ose affirmer que 
toute fonction pouvait etre representee entre et 2 tt par un developpe- 
ment de cette nature, et, ce qui est le point capital, qu'un meme de- 
veloppement pouvait entre ces limites representer des fonctions qu'on 
considerait comma distinctes, c'est a dire correspondant graphiquement 
a des arcs de courbes differentes. II est tres instructif d'etudier dans 
la theorie de la chaleur de Fourier les voies diverses que le celebre geo- 
metre a suivies pour avoir les coefficients du developpement. La determi- 
nation de ces coefficients a I'aide des integrales classiques ne vient qu'en 



Premiere Conference. 209 

second lieu ; cette determination avait d'ailleurs ete indiquee auparavant, 
quoique d'une maniere incidente, par Euler. Dans une premiere methods, 
Fourier obtient les coefficients en envisageant une infinite d'equations du 
premier degre a une infinite d'inconnues ; c'etait une recherche audacieuse 
pour I'epoque, et nous ne devons pas nous attendre a trouver dans cette 
etude toiite la rigueur que nous exigeons aujourd'hui. II n'en faut pas 
moins se souvenir que Fourier eut le premier la hardiesse de resoudre des 
systemes d'une infinite d'equations lineaires a une infinite d'inconnues. 
II y a d'ailleurs en analyse plus d'une question ou se presentent de tels 
systemes. C'est le cas quand on veut chercher le developpement du quo- 
tient de deux series trigonometriques, et aussi, quand ayant a integrer 
une equation differentielle lineaire a coefficients periodiques, on veut y 
satisfaire par une f onction periodique ou au moyen du produit d'une telle 
fonction par une exponentielle ; ce dernier cas se presente dans plusieurs 
problemes de mecanique celeste et en particulier dans les beaux travaux 
de M. Hill sur le mouvement du perigee de la lune. M. Poincare a pose 
les principes d'une etude rigoureuse des systemes d'equations en nombre 
infini, specialement dans le cas des systemes homogenes. II introduit 
dans cette theorie les determinants d'ordre infini, et un fait inattendu 
ressort de ses recherches, a savoir que des egalites en nombre infini 
peuvent dans certains cas etre remplacees par une infinite d'inegalites. 
II y a d'aillem's en analyse bien d'autres questions ou on se trouve en 
presence d'une infinite d'equations et il y aura un jour un chapitre interes- 
sant a ecrire sur I'integration d'un nombre infini d'equations differentielles 
avec une infinite de fonctions inconnues. Mais revenons aux series trigo- 
nometriques. En poursuivant rapidement leur histoire, nous arrivons a 
la periode oii Cauchy, Abel, et Dirichlet soumettent a une revision severe 
les principes fondamentaux de I'analyse mathematique. Le memoire de 
Dirichlet sur les series de Fourier est reste un modele de rigueur ; 
I'illustre auteur precise les conditions pour que I'on puisse affirmer qu'uu 
developpement trigonometrique avec les coefficients de Fourier represente 
une fonction donnee dans I'intervalle de a 2 tt, et ces conditions sont 
restees dans la science sous le nom de conditions de Dirichlet. EUes sont 
seulement suffisantes, mais on ne peut esperer dans cette theorie trouver, 
sous une forme pratique, des conditions a la fois hecessaires et suffisantes. 
II est certain aujourd'hui, grace surtout aux travaux de Du Bois-Reymond, 
qu'une fonction continue n'est pas necessairement toujours developpable 
en serie trigonometrique ; la condition suffisante de M. Lipschitz f ormulee 



210 Emile Picard: 

par I'inegalite [/(a; + A) — /(a;)] <M°(a > 0), en designant par k une 
constante fixe, a un grand caractere de generalite, et il en est de meme 
du theoreme de M. Camille Jordan sur la legitimite du developpement 
pour les fonctions a variation bornee. 

Le memoire de Riemann sur les series trigonometriques est celebre 
dans I'histoire de ces series ; on peut dire en deux mots, pour le carac- 
teriser, qu'il abandonne le point de vue de Dirichlet, et qu'au lieu de 
chercher des conditions suffisantes, sa principale preoccupation est de 
trouver des conditions necessaires. A un autre point de vue encore, le 
memoire de Riemann marque une date parce qu'il continue cette revision 
des principes du calcul infinitesimal commencee par Abel et Cauchy ; la 
distinction entre les fonctions integrables et les fonctions non integrables 
y apparait pour la premiere fois, et on peut dire qu'il resulte des travaux 
de Riemann qu'il y a des fonctions continues n'ayant pas de derivees. 

On doit a M. G. Cantor la reponse a une question importante : une 
fonction peut-elle etre representee entre et 2 tt de plusieurs manieres 
par une serie trigonometrique ? En d'autres termes, zero peut-il etre 
represente par un developpement trigonometrique ou les coefficients ne 
soient pas tous nuls ? Independamment du resultat lui-meme, le memoire 
de M. Cantor est digne d'interet parce que, dans une question depuis 
longtemps posee, des notions concernant les ensembles de points viennent 
jouer un role utile. Etant donne un ensemble de points entre et 2 tt, 
M. Cantor appelle ensemble derive 1' ensemble de ses points limites, et 
on peut definir ainsi de procbe en proche les derivees successives d'un 
ensemble. Si la derivee n*™^ d'un ensemble se reduit a un nombre 
limite de points, I'ensemble sera dit de la w*'"" espece. M. Cantor etablit 
que si dans I'intervale (0, 2 tt) une serie trigonometrique est nuUe pour 
toutes les valeurs de a; a I'exception de celles qui correspondent aux 
points d'un ensemble d'espece n, pour lequel on ne salt rien de la serie 
tous les coefficients seront nuls. 



J'ai insiste, peut-etre un peu longuement, sur les series trigono 
metriques. Independamment de leur importance dans les applications 
et particulierement en physique mathematique, elles ont joue un role 
considerable dans revolution de la notion de fonction ; c'est leur etude 
qui a appele 1' attention sur des circonstances, qui ne nous etonnent plus 
aujourd'hui, mais qui paraissaient jadis invraisemblables, comme, par 



Premiere Conference. 211 

exemple, ce fait que la limite vers laquelle tend une serie de fonctions 
continues peut n'etre pas egale a la valeur de la serie en ce point. Les 
precautions a prendre dans la derivation des series ont ete aussi sug- 
gerees par les series trigonometriques ; on peut faire remonter a cet 
exemple les nombreuses recherches effectuees depuis Cauchy sur la deri- 
vation et I'integration des series, auxquelles M. Osgood ajoutait il y 
a quelques annees un important complement dans son memoire sur la 
convergence non-uniforme. 

Le developpement d'une fonction en serie trigonometrique est aussi 
le type le plus simple de developpements tres generaux qui se presen- 
tent dans les applications ; Fourier, ici encore, a ete un precurseur. 
L'etude du refroidissement d'une sphere, en supposant que la tempera- 
ture ne depende que du temps et de la distance au centre, I'a conduit 
a un developpement ou, au lieu des lignes trigonometriques des multiples 
X, 2z, •••, nx de la variable, figurent les lignes trigonometriques de a-^x, 
a^x, ■■; a„x, les a designant les racines en nombre infini d'une certaine 
equation transcendante, et il a esquisse une theorie de ces sortes de 
developpements. Cette etude a et^ reprise par Cauchy dans plusieurs 
memoires qui forment une des applications les plus remarquables de ce 
que le grand analyste appelait le calcul des residus. Sous des conditions 
tres generales relatives a I'equation transcendante, Cauchy a demontre 
en toute rigueur la legitimite des developpements pour une fonction 
satisfaisant d'ailleurs aux conditions de Dirichlet, et ainsi se sont trouves 
considerablement generalises les resultats du memoire classique de I'il- 
lustre geometre allemand. 

D'autres developpements d'un caractere encore plus general se ren- 
contrent en physique mathematique, et ont fait I'objet des travaux de 
Poisson, de Sturm et de Liouville et de bien d'autres, mais ici se pre- 
sentent, au point de vue de la rigueur complete, des difficultes que Ton 
a reussi a surmonter que dans un petit nombre de cas. Je citerai seule- 
ment I'exemple tres simple du refroidissement d'un mur indefini dont 
les faces extremes sont maintenues a la temperature zero ; on suppose 
d'ailleurs que la chaleur specifique soit une fonction de I'abscisse x cor- 
respondant a chaque tranche, de telle sorte que I'on a pour la tempera- 
ture V I'equation aux derivees partielles 

— - = A(x) — -, 
dx^ ^ ^ dt 



212 Emile Picard : 

ou Aix) est une fouction continue et positive de x dans rintervalle (a, J) 
de I'epaisseur du mur. Envisageons I'equation lineaire ordinaire 

et les valeurs positives de k en nombre infini, Atj, h^-, •••, h„ •••, pour les- 
quelles il existe une integrale de I'equation precedente s'annulant en 
a et J. A chaque valeur de Aj correspond une integrale y-^(x') de cette 
equation (determinee a une constante pres), et le probleme qui se pre- 
sents est de developper une fonction f(x) s'annulant en a et 6 sous la 
forme 

f(x) = %B,y^(x). 

La demonstration rigoureuse de ce developpement resulte des der- 
nieres recherches de M. Stekloff, s'aidant des travaux anterieurs de M. 
Poincare sur les equations de la physique mathematique. II semble bien 
qu'il soit indispensable pour I'entiere rigueur de supposer que f(x) a des 
derivees des deux premiers ordres ; nous sommes loin d'atteindre ici a la 
generalite des conditions de Dirichlet pour le developpement en serie 
trigonometrique qui rentre d'ailleurs comme cas particulier (celui ou 
Aix) est une constante) dans le cas precedent. 



L'histoire des developpements en series que je viens de retracer rapide- 
ment nous donne un remarquable exemple de I'intime solidarite qui unit 
a certains moments 1' analyse pure et les matliematiques appliquees. En 
plus d'une occasion, ce sont celles-ci qui out donne I'impulsion en posant 
les problemes, et c'est un fait assurement remarquable que des questions 
concernant les cordes vibrantes ou la propagation de la chaleur aient 
conduit les geometres a approfondir la notion si complexe de fonction. 
L'histoire de la science mathematique offrirait d'ailleurs des le debut 
des exemples analogues ; nos facultes d'abstraction ne trouvent primi- 
tivement a s'exercer qu'en partant de certains faits concrets, et c'est sans 
doute en reflechissant aux procedes empiriques des praticiens egyptiens 
leurs predecesseurs que les premiers geometres grecs creerent la science 
geometrique. Mais ces vues risqueraient de m'entrainer trop loin. Je 
tiens seulement a ajouter qu'il ne faudrait pas professer une opinion trop 
systematique sur cette marche parallele de la theorie pure et des applica- 
tions, comme le faisait avec Laplace, Fourier, Poisson la brillante ecole 



Premiere Conference. 213 

frangaise de physique mathematique du commencement de ce siecle. 
Pour eux, I'analyse pure n'etait que I'instrument, et Fourier, en annon- 
gant a I'Academie des sciences, les travaux de Jacobi, disait que les ques- 
tions de la philosophie naturelle doivent etre le principal objet des 
meditations des geometres. " On doit desirer, ajoutait-il, que les personnes 
les plus propres a perfectionner la science du calcul dirigent leurs tra- 
vaux vers ces hautes applications si necessaires au progres de I'intelli- 
gence humaine." Ce desir tres legitime ne doit pas etre exclusif ; ce 
serait meconnaitre d'abord la valeur philosophique et artistique des 
mathematiques ; de plus des speculations theoriques sont restees pendant 
longtemps eloignees de toute application, quand un moment est venu ou 
elles ont pu etre utilisees. On n'en pent pas citer d'exemple plus 
memorable que le concept des sections coniques elabore par les geometres 
grecs, qui resta inutilise pendant deux mille ans, jusqu'au jour ou Kepler 
s'en servit dans I'etude de la planete Mars. Les questions s'epuisent 
pour un temps, et il n'est pas bon que tous les chercheurs marchent dans 
la meme voie. Peu d'annees apres que Fourier ecrivait les lignes que 
je viens de rappeler, apparaissait Evariste Galois qui aurait, s'il avait 
vecu davantage, retabli I'equilibre en ramenant les recherches vers les 
regions les plus elevees de la theorie pure, et ce fut un malheur irre- 
parable pour la science frangaise que la mort de Galois, dont le genie 
allait exercer une action si profonde sur les parties les plus varices des 
mathematiques. 

Avec cette digression, nous semblons etre bien loin, messieurs, de notre 
promenade a travers I'idee de fonction depuis le commencement de ce 
siecle. Ella n'etait cependant pas inutile, pour montrer qu'un moment 
devait arriver ou les speculations sur la theorie des fonctions de variables 
reelles se poursuivraient sans souci immediat des applications et pren- 
draient de plus en plus un caractere philosophique. Nous avons deja dit 
qu'il resultait indirectement des travaux de Eiemann qu'une fonction con- 
tinue n'a pas necessairement une derivee. Weierstrass donna le premier 
exemple d'une fonction continue n'ayant de derivee pour aucune valeur 
de la variable, et il fit connaitre au sujet des fonctions continues une 
proposition qui nous ramene aux developpements en series, mais ici les 
termes sont des polynomes. D'apres "Weierstrass, toute fonction con- 
tinue dans un intervalle pent etre developpee en une serie de polynomes 
qui est absolument et uniformement convergente dans cet intervalle. 
La demonstration de I'illustre geometre est tres compliquee ; elle prend 



214 JEmile Picard: 

comme point de depart une integrale consideree par Fourier dans la 
theorie de la chaleur, qui permet d'obtenir la fonction consideree comme 
la limite d'une fonction transeendante entiere dependant d'un parametre, 
quand celui-ci tend vers zero. C'est de la que Weierstrass deduit la 
possibilite de representer d'une maniere approchee par un polyuome 
toute fonction continue dans un intervalle iini, d'ou se tire alors de suite 
le resultat enonce. On peut arriver beaucoup plus rapidement au 
theoreme de Weierstrass en partant de I'integrale classique de Poisson 
dans la theorie des series trigonometriques ; elle montre facilement que 
la fonction, supposee definie dans un intervalle moindre que 2 tt, peut-etre 
representee avec telle approximation que Ton voudra par une serie 
limitee de Fourier, et on passe de suite a une representation approchee 
par un polynome ; celle demonstration s'etend a des fonctions continues 
d'un nombre quelconque de variables. M. Volterra est arrive aussi tres 
simplement au theoreme qui nous occupe en remarquant qu'une fonction 
continue est representable avec telle approximation qu'on voudra par 
une ligne polygonale convenable ; celle-ci conduit a une serie de Fourier 
uniformement convergente, et en la reduisant a un nombre suffisamment 
grand mais limite de termes on retombe sur le resultat indique plus 
haut. Le theoreme de Weierstrass presente un reel interet philosophique, 
en meme temps qu'il peut avoir quelque utilite au point de vue du cal- 
cul pratique ; on en a aussi quelquefois fait usage pour la demonstration 
de certaines propositions. 

Les developpements en series de polynomes speciaux sont d'un grand 
interet, mais ils ne peuvent s'appliquer qu'a des fonctions satisfaisant 
a des conditions particulieres. Ainsi, dans son memoire sur I'ap- 
proximation des fonctions de tres grands nombres, M. Darboux a 
etudie les developpements d'une fonction suivant les polynomes de Jacobi 
provenant de la serie hypergeometrique. Les conditions sont encore 
celles de Dirichlet ; pareillement aussi dans le cas ou la fonction devient 
infinie, elle doit rester integrable. H y a cependent une difference quand 
la fonction devient infinie pour les points extremes. Dans le cas des 
polynomes de Legendre, une fonction qui deviendrait infinie d'un ordre 
egal ou superieur a -I pour a; = ± 1 ne serait pas developpable, quoique 
les coefficients aient un sens. 

IV. 

Si nous revenons aux fonctions prises dans toute leur generalite, on 
reconnait vite la necessite d'etablir avec un soin extreme certaines pro- 



Premiere Conference. 215 

positions que Ton accorde aisement pour les fonctions usuelles. C'est ce 
qu'avait deja reconnu Cauchy dans son Analyse algebrique ; les travaux 
de Hankel, le memoirs de M. Darboux sur les fonctions discontinues, le 
beau livre de M. Dini et les etudes plus recentes des geometres italiens 
montrent bien les precautions necessaires dans ce genre de recherches. 
Ainsi, une fonction de deux variables reelles peut etre continue par rap- 
port a a; et par rapport a y sans etre continue par rapport a I'ensemble 
des deux variables, comme M. Dini en a indique des exemples. Parmi 
les travaux les plus recents sur ces questions delicates, je m'arreterai un 
instant sur un memoire de M. Baire qui renferme de curieux resultats. 
L'auteur a reussi a trouver la condition necessaire et suffisante pour qu'une 
fonction f(x) d'une variable reelle puisse etre representee par une serie 
simple de polynomes ; Fenonce suppose certaines notions sur la discon- 
tinuite d'une fonction par rapport a un ensemble de points : une fonction 
peut etre ponctuellement ou totalement discontinue par rapport a cet 
ensemble. La condition obtenne est que la fonction soit ponctuellement 
discontinue par rapport a tout ensemble parfait. M. Baire se pose aussi 
une question singuliere sur les equations lineaires aux derivees partielles. 
Envisageons I'equation 

Si je vous demandais quelles sont les fonctions satisfaisant a cette 
equation, vous me repondriez sans doute que les fonctions Ae x~ y 
repondent seules a la question. M. Baire n'en est pas absolument sur ; 
il remarque que la theorie du changement de variables suppose la con- 
tinuite des derivees qu'on emploie; si on suppose seulement I'existence 

des derivees -^ et — de la fonction cherchee /, on ne peut pas faire le 
dx dy 

changement de variables classique. II faut une analyse delicate pour 
etablir que la fonction /, supposee continue par rapport a I'ensemble des 
variables x et y, et satisfaisant a (1) est une fonction de x — y ; la conclu- 
sion reste douteuse si / est seulement continue par rapport a a; et par 
rapport a y. 

Au point de vue geometrique les recherches generales sur les fonctions 
ne sont pas non plus sans interet ; elles nous apprennent a nous defier de 
nos conceptions les plus simples. Quoi de plus simple serable-t-il qu'une 
courbe dont les coordonnees x ety sont des fonctions continues d'un para- 
metre t variant entre a et b. M. Peano a cependant montre qu'on peut 



216 Emile Pkard: 

choisir ces deux fonctioiis de telle sorte que, quand t varie entre a et J, le 
point (x, «/) puisse prendre une position quelconque dans un rectangle. 
A certains points (x, y) pourront correspondre d'ailleurs, dans I'exemple 
de M. Peano, deux ou quatre valeurs de t. Ce resultat est au premier 
abord deconcertant ; il derange nos idees sur les surfaces et sur les 
courbes. Voici encore un resultat singulier obtenu tout recemment par 
M. Lebegue ; il y a d'autres surfaces que les surfaces developpables qui 
sont applicables sur un plan. On pent a I'aide de fonctions continues 
obtenir des surfaces correspondant a un plan de telle sorte que toute ligne 
rectifiable du plan ait pour correspondante une ligne rectifiable de la 
surface, et la surface n'est cependant pas reglee. 

De tels exemples montrent la subtilite des recherches auxquelles 
doivent se livrer aujourd'hui ceux qui veulent approfondir la notion de 
fonction prise dans son extreme generalite. Ces etudes sont en bien des 
points intimement liees aux speculations sur la notion meme de nombre. 
Nous rejoignons ici une ecole de philosophic mathematique qui s'est 
brillamment developpee depuis quelque trente ans, ecole qui se livre a 
une minutieuse analyse sur la nature du nombre. On ne pent s'empecher 
d'etre frappe du nombre considerable de publications parues dans ces 
dernieres annees et se rapportant a cette mathematique philosophique ; 
elles sont bien en accord avec les tendances generales de I'epoque ou nous 
vivons, et ou I'esprit humain applique dans des directions varices une 
critique de plus en plus penetrante. Ces speculations raffinees ont meme 
penetre dans I'enseignement elementaire, ce qui est a men avis tres 
regrettable. Mais il ne s'agit pas ici d'enseignement ; je ne recherche 
pas non plus I'interet que ces etudes presentent pour le philosophe ; il me 
parait tres reel, et on doit souhaiter que de jevines philosophes s'engagent 
dans cette direction apres s'etre inities serieusement aux mathematiques. 
Je ne veux me placer qu'au point de vue de la mathematique. De bons 
esprits contestent que les speculations dont je parle aient quelque impor- 
tance pour les mathematiques positives et ils craignent de voir beaucoup 
de talent depense dans des recherches steriles. Je comprends tres bien 
leurs craintes mais je ne partage pas entierement leur avis. II y a lieu 
sans doute de faire des distinctions. Certaines questions sont d'un interet 
purement philosophique et n'auront jamais vraisemblablement la moindre 
utilite pour les mathematiques, comme, par exemple, de savoir si la priorite 
appartient au nombre cardinal ou au nombre ordinal, c'est a dire si I'idee 
de nombre proprement dit est anterieur a celle de rang ou si c'est 



Premiere Confhence. 217 

I'inverse. Mais dans d'autres cas, il n'en est plus de meme ; ainsi il est 
vraisemblable que la theorie des ensembles de M. Cantor, que nous avons 
deja rencontree deux fois sur notre chemin, est a la veille de jouer un 
role utile dans des problemes qui n'ont pas ete poses expres pour etre une 
application de la theorie. Ne regrettons done pas cet effort hardi sur 
I'idee de nombre et sur celle de fonction, car la theorie des fonctions de 
variables reelles est la veritable base de 1' analyse mathematique. 

V. 

II faut bien, il est vrai, reconnaitre que la notion generale de fonction 
est tres vague, et nous ne pouvons obtenir des resultats de quelque 
etendue qu'en faisant des hypotheses particulieres. Qu'est ce qui a guide 
plus ou moins consciemment dans le choix de ces hypotheses ? II resulte 
de ce que nous avons dit sur les rapports entre I'analyse et les applica- 
tions aux phenomenes naturels, que celles-ci ont plus d'une fois guide le 
mathematicien dans son choix. Une hypothese essentielle a ete celle de 
la continuite. Suivant le vieil adage "natura non facit saltus" nous 
avons le sentiment, on pourrait dire la croyance, que dans la nature il n'y 
a pas de place pour la discontinuite. II est utile quelquefois de conserver 
le discontinu dans nos calculs, par exemple quand nous regardons comme 
nuUe la duree du choc en mecanique rationnelle, ou quand nous reduisons 
a une surface les couches de passage dans plusieurs questions de physique ; 
mais nous savons que, pour si petite qu'elle soit, les chocs ont une certaine 
duree et les physiciens nous ont appris a mesurer I'epaisseur des couches 
ou se produisent dans plusieurs phenomenes des variations tres rapides. 
L'idee de derivee s'impose deja moins; elle repond cependant au senti- 
ment confus de la rapidite plus ou moins grande avec laquelle s'accomplit 
tel ou tel phenomene. L'hypothese relative a la possibilite de la deriva- 
tion d'une fonction a done une origine analogue a celle de la continuite. 
Je ne veux pas dire qu'au point de vue du nombre l'idee de continuite soit 
aussi claire au fond qu'elle en a I'air, mais il ne s'agit ici que de la notion 
du continu physique tiree des donnees brutes des sens. 

Dans d'autres cas, on ne voit pas de cause du meme ordre dans la 
particularite imposee a la fonction ; il en est ainsi, ce me semble, pour la 
propriete des fonctions dites analytiques c'est a dire des fonctions qui 
dans le voisinage d'une valeur arbitraire de la variable peuvent etre 
developpees en series de Taylor. Les fonctions etudiees les premieres, 
comme les fonctions rationnelles, I'exponentielle, les lignes trigonome- 



218 Emile Picard: 

triques, jouissant de cette propriete, rattention se sera sans doute trouvee 
appelee sur elle; et ensuite la facilite avec laquelle cette hypothese a 
permis d'aborder certaines questions a fait acquerir aux fonctions analy- 
tiques une importance considerable. C'est done a leux commodite dans 
nos calculs qu'elles doivent le grand role qu'elles jouent. 

On ne salt pas d'aUleurs, pour une fonction definie seulement pour les 
valeurs reelles de la variable, quelles sont les conditions de legitimite du 
developpement en serie de Taylor. Une fonction de x pent avoir des 
derivees de tout ordre pour toute valeur de la variable, et n'etre cependant 
pas developpable. On doit a M. Borel un resultat remarquable con- 
cernant les fonctions d'une variable reelle definie dans un certain inter- 
valle et ayant dans cet intervalle des derivees de tout ordre. Si I'intervalle 
est (— TT, +7r), la fonction pent etre representee par un developpement 
de la forme 



n=0 



(J.„a;" + B^ cos nx + (7„ sin nx). 



Ces diverses remarques m'amenent a dire un mot d'une ecole de geo- 
metres qui ne veulent rien voir en dehors des fonctions analytiques, et 
d'une maniere plus generale de I'importance, peut-etre exageree, qu'a prise 
dans les travaux modernes la theorie des fonctions analytiques. C'est 
mutiler singulierement I'analyse que de vouloir se borner a des deve- 
loppements aussi particuliers que les series entieres, alors que Ton peut 
former tant de developpements d'une autre nature qui ne peuvent jamais 
etre representees par de telles series. Sans doute, les fonctions les plus 
usuelles sont analytiques, et on pourrait nous demander de citer des 
exemples dans la solution desquels interviennent des fonctions non analy- 
tiques, tandis que les donnees sont analytiques. lis ne sont pas courants ; 
ce sont les equations aux derivees partielles qui probablement les four- 
niront le plus facilement. Le suivant, dii a M. Borel, me parait digne 
d'etre signale. Envisageons I'equation 

oil a est une irrationnelle convenablement choisie, et f(x, y) une certaine 
fonction analytique de a; et «/ de periode 2 it pour x et y. Pour I'equation 
de cette forme citee par M. Borel, il y a une seule solution periodique et 
cette solution n'est pas analytique. Soit a un nombre incommensurable 



Premiere Conference. 219 

tel que — ^ etant I'une quelconque des reduites du developpement de a en 
fraction continue, on ait 

I Wlj — %a I < g-mf-na 

on forme 

(x, «/) = 2 «"'i5"'- cos (Wj^a;) cos (n^y') (a < 1, S < 1). 

C'est une fonction non analytique. Posons d'autre part 

^--^^-t(^,J/), (1) 

la fonction i/r sera analytique. Done si on prend I'equation (1) a priori 
et qu'on cherche une solution periodique, en x et y, il n'y en a qu'une ; 
c'est ^ qui n'est pas analytique. 

C'est encore, en se plagant a un autre point de vue, qu'il parait 
mauvais de reduire la theorie des fonctious a la theorie des fonctions 
analytiques. H y a de nombreuses questions, oii le fait pour les donnees 
d'etre analytiques ne donne aucune facilite pour la solution, et ou on 
risque, en portant trop son attention sur cette nature des donnees, de 
cliereher la solution dans des voies sans issues. Pour le probleme du 
refroidissement de la barre dont je parlais plus haut, qu'importe que les 
fonctions donnees A(x') et /(a;) soient ou non analytiques ? Ce n'est pas 
tout ; il y a un dernier point sur lequel je tiens a insister. II pent arriver 
que la circonstance d'avoir a faire a des fonctions analytiques conduise a 
une solution, mais il se peut que celle-ci ne se presente pas sous la forme 
la plus favorable, forme a laquelle on arrive au contraire en faisant ab- 
straction de la nature analytique des donnees. La theorie des equations 
differeatielles fournirait des exemples a I'appui de cette assertion; bornons 
nous a citer le theoreme fondamental du Calcul Integral relatif a 1' ex- 
istence de I'integrale de I'equation differentielle -^=f(x,y'). Ce sont 

dx 
les demonstrations ne supposant pas que la fonction / soit analytique, 
qui donnent le plus grand intervalle comme region ou I'integrale est 
certainement determinee ; I'analyste, qui suppose analytique la fonction 
reelle f(x, y^) et veut n'envisager que des series entieres, est conduit par 
son mode de demonstration a un domaine plus restreint. 

J'ai simplement eu pour but dans ce qui precede de montrer qu'il ne 
faut pas restreindre systematiquement la notion de fonction. D'une 
maniere generale, admirons des systemes tres bien ordonnes, mais mefions 
nous un peu de leur apparence scolastique, qui risque d'etouffer I'esprit 



220 Emile Picard: 

d'invention. II ne s'agit pas, bien entendu, de nier la grande importance 
actuelle de la theorie des fonctions analytiques, mais il ne faut pas oublier 
qu'elles ne forment qu'une classe tres particuliere de fonctions, et on doit 
souhaiter qu'un jour vienne ou les mathematiciens elaborent des theories 
de plus en plus comprehensives ; o'est ce qui arrivera peut-etre au siecle 
prochain, si I'idee de fonction, dont je vous ai bien incompletement 
esquisse I'histoire, continue son evolution. Mais, pour le moment nous 
sommes encore au dix-neiivieme siecle ; j'aurai I'occasion demain et apres 
demain de faire amende honorable aux fonctions analytiques, qui depuis 
trente ans ont fait, comme vous savez, I'objet de travaux considerables. 



Nous venons de voir les vastes perspectives qu'ouvre I'extension de 
plus en plus grande de la notion de fonction. II faudra certainement 
montrer dans cette voie beaucoup de prudence, et ne pas entreprendre 
avant I'heure des recherches qui resteraient steriles ; mais il n'est pas 
douteux qu'un jour viendra oii I'analyste sentira le besoin d'etendre le 
domaine de ses recherches. L'extension de I'idee de fonction n'est pas la 
seule qu'aient poursuivie en ce siecle les mathematiciens qui s'interessent 
aux principes de la science ; la question des quantites complexes a vive- 
ment excite I'interet, d'autant plus qu'une certaine obscurite planait sur 
elle, qu'entrainait le mot un peu mysterieux de quantites imaginaires. 
Le sujet ne presente phis rien aujourd'hui de mysterieux. Dans un 
memoire publie en 1884 Weierstrass a developpe une theorie des nombres 
complexes. II suppose que Ton considere des nombres de la forme 



ajjfij + x^e^ + •■■ + x„. 



oil les X sont des nombres reels on imaginaires ordinaires. Les e sont de 
purs symboles. On fait I'hypothese que la somme, la difference, le pro- 
duit et le quotient de deux nombres de I'ensemble font eux-memes partie 
de cet ensemble. Les produits e.pe^ (^p, q = 1, 2, •■-, ?i) sont done des 
expressions Up^^ lineaires et homogenes en e-^, gg, •••, e„ qui jouent le role 
essentiel dans la theorie. Weierstrass suppose de plus que les theoremes 
dits commutatif et associatif subsistent tant pour I'addition que pour la 
multiplication. Pour I'addition, ils sont verifies d'eux-memes ; pour la 
multiplication, ils s'expriment par les egalites 

ah = ha, (^ah) . o = a • (5c), 



Premiere Conference. 221 

a, 5, c etant trois nombres quelconques de Tensemble. Ces conditions 
conduisent a certaines relations entre les coefficients des formes lineaires 
Hp^q- A tout systeme de formes Ej,^^ verifiant ces conditions corre- 
spondra un ensemble de nombres complexes. Les nombres complexes 
que nous venons de definir different seulement en un point des nombres 
complexes ordinaires. Quand n est superieur a deux, il peut exister des 
nombres differents de zero dont le produit par certains autres nombres 
est nul. Weierstrass appelle ces nombres des diviseurs de zero. M. 
Dedekind a montre qu'en general les calculs avec ces nombres complexes 
se ramenaient aux calculs de I'algebre ordinaire ; d'une maniere plus 
precise, si le carre d'un nombre ne peut etre nul sans que ce nombre soit 
nul, on peut aux n unites complexes primitives substituer n autres unites 
(le determinant de la substitution n'etant pas nul) de telle sorte que pour 
ces nouvelles unites e\, e'^, ■•; e'„, on ait 

d'ou Ton conclut que les calculs relatifs aux nombres complexes prece- 
dents se ramenent a des calculs relatifs aux nombres reels ou complexes 
ordinaires. 

Nous avons admis que les lois commutative et associative subsis- 
taient dans I'algebre precedente. On s'est place a un point de vue plus 
general en supposant que, seule, la loi associative subsistait [c'est a dire 
(a6)c = a(6c)]. On a alors une algebre beaucoup plus generale ; celle-ci 
est completement determinee par le systeme des expressions lineaires 
Ep^^. Un exemple celebre d'un systeme a quatre unites ej, e^^, e^, e^ est 
fourni par les quaternions d'Hamilton 

e^ =1, ^2 = ■^i ^3 = i' ^4 = ^» 
avec les relations i^ = j^ = k"^ = —1 

V = — ji = * 
jk = — kj = i 
ki = — ik = j. 

Une remarque tres interessante de M. Poincare ramene toute la 
theorie des quantites complexes a une question concernant la theorie des 
groupes. EUe consiste en ce qu'a chaque systeme d'unites complexes 
correspond un groupe continu (au sens de Lie) de substitutions lineaires 



222 Emile Picard : 

a n variables, dont les coefficients sont des fonctions lineaires de n para- 
metres arbitraires, et inversement. Cette idee a ete approfondie par 
M. Scheffers qui a ete ainsi conduit a partager les nombres complexes 
en deux classes, suivant que le groupe qui leur correspond est integrable 
ou non integrable. A cette derniere classe appartient le groupe corres- 
pondant aux quaternions, et ceux-ci sont les representants les plus simples 
de cette categoric de nombres complexes. Le rapprochement entre la 
theorie des groupes de Lie et les nombres complexes fait disparaitre 
le mystere qui semblait planer sur ceux-ci, et la veritable origine des 
symboles est ainsi bien mise en evidence. On peut se demander si ce 
symbolisme est susceptible d'accroitre la puissance de I'Analyse. En 
France, les geometres qui s'interessent a ces calculs sont tres peu nom- 
breux ; je sais qu'au contraire en Angleterre et, je crois aussi, dans ce 
pays les quaternions sont tres apprecies. Je ne les ai pas assez manies 
moi-meme, pour me rendre compte si leur emploi en mecanique ou en 
physique mathematique simplifie les calculs d'une maniere tres appre- 
ciable ; il y a probablement la surtout une affaire d'habitude. Le point 
vraiment interessant serait de savoir si ces quantites complexes presen- 
teront un jour quelque interet pour 1' analyse generale, comme il arrive 
pour les imaginaires ordinaires. Les essais tentes jusqu'ici dans cette voie 
ne paraissent pas avoir ete heureux ; mais, maintenant que le lien avec 
la theorie des groupes est completement mis en evidence, il n'est pas 
impossible que de nouvelles tentatives n'aboutissent a quelque resultat 
interessant. 

Les idees de nombres reel ou complexe, la notion de fonction sont 
a la base meme de I'analyse ; il y a encore une autre notion que le travail 
mathematique de ce siecle a conduit a elargir considerablement. L'idee 
d'espace forme la matiere meme de la geometric ; elle aussi a ete sou- 
mise a une critique penetrante qui a renouvele les bases de la geometric. 
Je n'en referai pas I'histoire depuis Gauss, Bolyai et Lobatschevski, his- 
toire tres souvent racontee, ni ne prendrai parti dans les querelles que 
se font encore a ce sujet les philosophes. Je veux dire seulement un 
mot de I'interet qu'ont eu pour les mathematiques les speculations sur 
la nature de I'espace. Dans le memoire cel^bre de Riemann, apparaissent 
pour la premiere fois les notions relatives a la courbure de I'espace dans 

les differentes directions, c'est-a-dire les „ — - fonctions invariantes 

caracteristiques d'lme multiplicite a n dimensions ; une vive impulsion 



Premiere Conference. 223 

a ete ainsi donnee a la theorie des formes quadratiques de differentielles. 
Pour ne citer qu'un exemple, j'indiquerai seulement la forme 

qui doime le carre de I'element d'arc dans la geometric de Lobatchevski ; 
et il est interessant de rappeler le role qu'elle a joue dans les recherehes 
de M. Poincare sur la formation des groupes fuchsiens. Apres Rie- 
mann, Helmholtz posa la question sur un autre terrain: son idee fonda- 
mentale consiste a porter I'attention sur I'ensemble des mouvements 
possibles dans I'espace dont on fait I'etude. Le grand pbysicien traitait 
ainsi par avance de problemes se rattachant a la theorie des groupes. 
Celle-ci n'etait pas encore creee a I'epoque oii Helmholtz ecrivait son 
memoire ; il a commis quelques erreurs apres tout secondaires, mais 
il n'en a pas moins la gloire d'avoir le premier regarde une geometric 
comme I'etude d'un groupe. Les recherehes d'Helmholtz furent reprises 
completement par Lie ; elles lui offraient une magnifique occasion d'ap- 
pliquer son admirable theorie des groupes de transformations. Dans 
ces etudes, I'espace est a priori regarde comme une multiplicite, et, en 
prenant le cas de trois dimensions, un point est defini par trois quantites 
(x, y, z). Un mouvement dans I'espace n'est autre chose qu'une trans- 
formation 

x' =f(x, y, z), y' = <}>(x, y, s), z' = -^(x, y, s) 

valable pour une portion de I'espace. On suppose que tons les mouve- 
ments possibles forment un groupe a six parametres, qu'ils laissent 
invariable une fonction des coordonnes de deux points quelconques, 
qu'enfin le mouvement libre soit possible, comme disait Helmholtz. Lie 
demontre alors que I'espace euclidien et les espaces non euclidiens sont 
les seuls qui satisfassent a ces conditions. Au point de vue oii s'est place 
Lie, I'etude des principes de la geometric pent etrc regardee comme 
epuisee, mais il se borne a considerer une petite portion dc I'espace. 
Clifford et Klein ont appele I'attention sur la question de la conncxite de 
I'espace qui est extremement interessante ; nous ne savons rien sur la 
conncxite de I'espace ou nous vivons. On pent aussi chercher a appro- 
fondir le postulat de I'espace regarde comme une multiplicite, et sub- 
ordonner la conception metrique de I'espace a la conception projective 
avec von Staudt, Cayley et Klein ; mais jc dois mc contenter de rappeler 
ces directions divcrses. 



224 Emile Picard: 

J'ai seulement, messieurs, voulu montrer dans cette conference quelles 
perspectives ouvre aux chercheurs I'extension de nos idees sur les fonc- 
tions, sur le nombre et sur I'espace. Si I'elaboration mathematique est 
aussi feconde au siecle prochain qu'elle I'a ete en ce siecle, I'analyse 
differera beaucoup dans cent ans de ce qu'elle est aujourd'hui ; on 
maniera peut-etre couramment les fonctions les plus extraordinaires, et 
on verra tres clair dans des espaces ayant beaucoup de dimensions et des 
connexites elevees. Pour se representer I'etat de la mathematique en 
Fan 2000, il faudrait I'imagination de I'auteur de "Looking Backward"; 
il est malheureux que M. Bellamy dans son roman ne nous ait pas parle 
des mathematiques a cette epoque. Comme Tbumanite, s'il faut I'en 
croire, aura alors beaucoup de loisirs, les mathematiques seront sans 
doute extremement florissantes et les problemes qui nous arretent aujour- 
d'hui ne seront plus que des jeux d'enfants pour nos successeurs. 

Sbcokdb Conference. 

Quelques Vues GienSrales sur la Theorie des Equations Differentielles. 

Je voudrais aujourd'hui jeter un coup d'ceil siu" la theorie des equa- 
tions differentielles, qui joue en analyse un role considerable et dont les 
progres importent vivement a ses applications ; c'est un domaine tres 
vaste et j'eprouve quelque embarras a faire un choix entre les directions 
si diverses oii s'est developpee cette theorie. Les geometres du siecle 
dernier ne paraissent pas s'etre preoccupes d'etablir rigoureusement 
I'existence des integrales des equations differentielles; ils integraient, 
quand ils le pouvaient, les equations qui se presentaient dans leurs 
recherches, sans se soucier de ces theoremes d' existence, comme on dit 
aujourd'hui, auxquels nous attachons beaucoup d'importance. C'est a 
Cauchy que i'on doit les premieres recherches precises sur ces questions ; 
le champ en est tres vaste, et il ne I'a pas parcouru en entier, mais, au 
moins dans le cas ou les fonctions et les donnees sont analytiques, il 
a indique les principes qu'ont suivis tons ses continuateurs. Dans les 
theoremes relatifs a I'existence des integrales, on emploie des methodes 
differentes suivant que les equations et les donnees sont supposees on non 
analytiques. 

I. 

Flagons nous d'abord dans le premier cas, de beaucoup le mieux 
elabore. L'idee essentielle de Cauchy consiste dans la consideration des 



Seconde Conference. 225 

fonctions majorantes. On sait que les difficultes resident surtout dans 
la demonstration de la convergence de certaines series entieres que les 
equations differentielles permettent de former. Cauchy y parvient par 
des comparaisons avec d'autres equations facilement integrables. Pour 
les equations differentielles ordinaires, il n'y avait a faire apres Cauchy 
que des simplifications de forme, et, pour le cas d'une seule equation aux 
derivees partielles, quel que soit le nombre des variables, le grand geo- 
metre avait indique aussi les points essentiels de la demonstration, que 
Mme. Kovalevski, dans un memoire reste classique, a presentee sous une 
forme tres simple. Le theoreme fondamental est alors le suivant : Si on 
a une equation aux derivees partielles d'ordre n relative a une fonction 
z de p + 1 variables independantes x, x-^, •••, x^ et que I'equation con- 

tienne la derives d'ordre n, - — , une integrale sera en general determinee 

si on se donne pour x = a les valeurs de s et de ses derivees par rapport 
a X jusqu'a I'ordre n — \-. ces donnees sont des fonctions holomorphes de 
ajj, x^^ •", Xp dans le voisinage de a;^, a^^ •••, a^. On peut done dire, en 
s'appuyant sur cet enonce que I'integrale generale de I'equation consideree 
depend de n fonctions de 'p variables independantes. C'etait un point 
auquel on tenait beaucoup autrefois de savoir de eombien de fonctions 
arbitraires dependait I'integrale generale d'une equation aux derivees 
partielles ; certains resultats paradoxaux avaient cependant deja appele 
I'attention comme les formes diverses de I'integrale generale de I'equation 

de la chaleur — ^ = — , qui se presentait tantot avec une, tantot avec 
do? By 

deux fonctions arbitraires. De tels resultats ne nous etonnent plus 
aujourd'hui, quand il s'agit comme ici de fonctions analytiques. Nous 
n'avons qu'a nous rappeler qu'un nombre fini quelconque de fonctions a 
un nombre quelconque de variables independantes ne presente pas, au 
point de vue arithmetique, une plus grande generalite qu'une seule fonc- 
tion d'une seule variable, puisque dans I'un et I'autre cas I'ensemble des 
coefficients des developpements forme simplement une suite enumerable. 
Aussi s'explique-t-on que M. Borel ait pu etablir que toute integrale 
analytique d'une equation aux derivees partielles a coefficients analy- 
tiques peut etre exprimee a I'aide d'une formule ne renfermant qu'une 
seule fonction arbitraire d'une variable reelle. 

Nous venons de considerer une seule equation aux derivees partielles. 
L'etude des systemes d'equations differentielles presentait de plus grandes 



226 Emile Picard: 

difficultes. Une premiere question est tout d'abord restee longtemps 
sans reponse ; il etait possible de se demander s'il pouvait exister des 
systemes qui comprennent un nombre illimite d'equations distinctes c'est 
a dire ne pouvant pas se deduire par differentiation d'un certain nombre 
d'entre elles. M. Tresse a etabli qu'un systeme d'eqiiations aux derivees 
partielles etant defini d'une maniere quelconque, ce systeme est necessaire- 
ment limite, c'est a dire qu'il existe un nombre fini s, tel que toutes les 
equations d'ordre superieur a s, que contient le systeme, se deduisent par 
de simples differentiations des equations d'ordre egal ou inferieur a s. 
II importait ensuite de se rendre compte de la nature des elements 
arbitraires figurant dans I'integrale generale. Mme. Kovalevski n'avait 
examine que certains systemes composes d'equations en nombre egal a 
celui des fonctions inconnues et resolubles par rapport aux derivees 
d'ordre le plus eleve de cbacune des fonctions, ces derivees etant relatives 
a une meme variable x. M. Riquier d'abord, puis M. Delassus ont donne 
sous des formes differentes la solution du probleme dans le cas general ; 
M. Delassus arrive par des changements de variables a obtenir une forme 
canonique completement integrable, et montre que I'integration d'un tel 
systeme a m variables se rameue a I'integration successive de m systemes 
de Mme. Kovalevski contenant successivement 1, 2, •••, m variables; c'est 
en partant de cette propriete qu'on peut demontrer facilement I'existence 
des integrales analytiques, et determiner les fonctions et constantes 
initiales en nombre fini dont dependent ces integrales. 

II semble y avoir eu longtemps cbez les matbematiciens quelques hesi- 
tations sur ce qu'on devait entendre par integrale generale d'une equation 
aux derivees partielles. Si I'on se borne aux cas oii il ne figure dans les 
equations que des elements analytiques, et si Ton n'envisage que les inte- 
grales analytiques, on considere aujourd'hui, conformement a I'opinion 
de M. Darboux, qu'une integrale est generale, si on peut disposer des 
arbitraires qui y figurent, fonctions et constantes, de maniere a retrouver 
les solutions dont les theoremes de Cauchy et de ses successeurs nous ont 
demontre I'existence. Anterieurement, Ampere s'etait place a un autre 
point de vue ; dans son grand memoire sur les equations aux differences 
partielles, il s'exprime ainsi : " Pour qu'une integrale soit generale, il faut 
qu'il n'en resulte entre les variables que Ton considere et leurs derivees a 
I'infini que les relations exprimees par I'equation donnee et par les equa- 
tions que Ton en deduit en la differentiant." II est bien clair qu'il s'agit 
de relations ne renfermant aucune des quantites arbitraires qui figurent 



Seconde Conference. 227 

dans I'integrale consideree. Les avis etaient partages entre les geometres, 
et on se demandait s'il y a identite entre la definition d' Ampere et celle 
de Caucliy. M. Goursat a montre bien nettement, sur differents exemples, 
qu'une integrale pent etre generale au sens d' Ampere sans etre generale 
au sens de Cauchy. 

II ne faudrait pas conclure des divers travaux qui precedent, que, tout 
en envisageant seulement des integrales et des equations analytiques, 
I'etude des conditions determinant les integrales d'un systeme d'equations 
aux derivees partielles soit actuellement aclievee. Les theoremes generaux 
indiques font connaitre certaines donnees qui determinent une integrale, 
mais celle-ci pent etre determinee par une infinite d'autres conditions. II 
n'est pas douteux que les types a trouver de ces theoremes d'existence 
sent en nombre infini. Prenons I'exemple tres simple de I'equation 

\- a ho \- cz = 0. 

dx dy dx oy 

Une integrale est determinee par la condition de se reduire pour a; = 
a une fonction donnee de y, et pour y = k une fonction donnee de x : 
voila un genre de determinations d'une integrale qui ne rentre pas dans 
les conditions du theoreme general de Cauchy. Les conditions tres 
varices, qui peuvent determiner les integrales des equations aux dif- 
ferences partielles appellent encore de nombreuses recherches. 



Nous venons de nous placer au point de vue de la theorie des fonctions 
analytiques. Comme je le disais liier, il y a souvent grand interet, non 
seulement a un point de vue philosophique, mais meme en quelque sorte 
au point de vue pratique, a adopter des hypotheses plus generales. C'est 
encore a Cauchy que Ton doit pour les equations differentielles ordinaires 
la demonstration de I'existence des integrales sans supposer les equations 
analytiques. Sa methode, bien naturelle et bien simple, consiste a 
regarder les equations differentielles comme limites d'equations aux 
differences. On pent faire sur cette methode de Cauchy une remarque 
tres interessante ; elle est susceptible de f ournir des developpements en 
series des integrales qui convergent tant que les integrales restent continues, 
et laissent continues les coefficients differentiels. En ce sens, elle est 



228 Emile Picard: 

superieure aux autres methodes qui ont ete proposees. Ainsi, pour 
prendre un exemple, soit le systeme d'equations 

-^ = ^i(.xv 2^2' •••' ^n) (i == 1, 2, — n) 

ou les X sont des polynomes. On pent representer les integrales de 
ce systeme prenant pour t=0 les valeurs x-^, x^, •••, xj^ par des deve- 
loppements de la forme 

PiCajjO, ^b^ ...^ 2;„o, + - + P„(V' ^2"^ -' ^^^ 0+ - 

les P etant des polynomes en a^j", x^, •••, xj^ et t, et ces developpements 
sont convergents tant que les integrales restent des fonctions continues 
de t. 

D'autres methodes ont ete proposees pour demontrer I'existence des 
integrales, comme la methode des approximations successives qui donne 
pour les series une convergence tres rapide, mais ces series ne convergent 
pas necessairement dans tout le champ ou les integrales sont continues. 

Pour une equation differentielle ordinaire d'ordre n, on suppose 
generalement, quand on veut etablir I'existence des integrales, qu'on se 
donne pour une valeur de x les valeurs de la fouction et de ses derivees 
jusqu'a I'ordre n— 1, mais on pourrait prendre beaucoup d'autres don- 
nees; et c'est ce qui arrive notamment dans les applications du calcul 
des variations. Ainsi pour une equation du second ordre, il arrive qu'une 
integrale soit determines par les conditions de prendre pour x^^ la valeur 
7/q et pour ajj la valeur yj. On a peu travaille jusqu'ici dans cet ordre 
d'idees, et cependant maintes conditions initiales sont aussi interessantes 
que celles adoptees dans le theoreme general classique. Les recherches 
entreprises dans cette voie ont conduit a quelques resultats par I'emploi 
de methodes d'approximations successives, et on a pu ainsi reconnaitre des 
cas singuliers de divergence dans I'emploi de ces methodes d'approximation. 

Si nous passons maintenant aux equations aux differences partielles, 
les equations et les donnees n' etant pas necessairement analytiques, nous 
nous trouvons dans un domaine tres etendu ou on n'a fait que les pre- 
miers pas. II faut deja quelque soin pour etablir I'existence des inte- 
grales de I'equation lineaire 

^+XCx,y}f = 
dx ^ ^-^dy 



Seconde Conference. 229 

sans supposer que X(x, y') soit analytique. Pour les equations d'ordre 
superieur, il n'y a qu'un petit nombre de types pour lesquels on puisse 
definir avec precision ce que Ton entend par integrale generale. lis ont 
generalement pour origine des problemes de geometrie infinitesimale 
ou de physique mathematique ; les variables et les fonctions restent ici 
reelles. Prenons, comme exemple, I'equation 

-^ + a— + 6 — + C2 = 
dxdy dx dy 

o\x. a, J, e sont des fonctions continues de x et y, sur laquelle Riemann 
a ecrit quelques pages extremement remarquables. Soit un arc de 
courbe MP tel que toute parallele a O2; et a Oy le rencontre au plus en 

dz 
un point ; nous nous donnons les valeurs de z et ^ sur cette courbe. 

II y aura une integrale et une seule, continue ainsi que ses derivees 
partielles du premier ordre, satisfaisant aux conditions donnees, et elle 
sera definie dans le rectangle de cotes paralleles aux axes et ayant M e,t P 
pour sommets opposes. On voit combien cet enonce est d'une nature 
plus precise que ceux qui ont ete donnes anterieurement en nous pla§ant 
au point de vue de la tbeorie des fonctions analytiques, ou pour une 
equation comme celle-ci on etablit seulement I'existence d'une solution 
dans le Toisinage d'une courbe, voisinage determine avec tres peu de 
precision. L'exemple si simple que nous avons choisi montre encore 
qu'il n'existe pas toujours d'integrale continue ainsi que ses derivees 
premieres satisfaisant aux conditions donnees sur un arc de courbe ; 
il en sera ainsi quand sur cet arc il y aura une tangente parallele a I'un 
des axes. Voici un second exemple dans le meme ordre d'idees ; on peut 
relativement a I'equation 

dx^ ■*" dy"^ dz^ ~ 

se donner les valeurs de u et de ^ pour les points d'un cercle O situe 

dans le plan z= z^; I'integrale ainsi definie est determinee a I'interieur 
des deux cones de revolution passant par la circonference et de gene- 
ratrices paralleles a celles du cone x"^ + y^ — z'^ = 0. 

Les conditions determinant une integrale peuvent prendre des formes 
tres diverses. Ainsi des conditions de continuite sont susceptibles de 
remplacer certaines donnees : c'est un fait auquel nous sommes tres 



230 Emile Picard : 

habitues, mais qui n'en est pas moins tres remarquable. L'equation du 
potentiel a provoq^ie dans cette voie de nombreuses rechercbes, et le 
tbeoreme fondamental auquel Riemann a donne le nom de Diricblet, 
apres avoir ete approfondi par Schwarz et Neumann, a encore fait recem- 
ment I'objet des rechercbes de M. Poincare. Des problemes analogues 
ont ete poses et resolus pour un grand nombre d'equations, par example 
pour l'equation 

S^u d^u du ,du „ 

ox' ay' ox by 

pour laquelle une integrale continue est determinee par ses valeurs sur 
un contour ferme dans toute region ou le coefBcient c est negatif ; de 
telles questions ne sont d'ailleurs pas limitees aux equations lineaires. 

Ces divers examples caracterisent bien la nature des tbeoremes d'exis- 
tence des integrales, quand on ne se place pas au point de vue de la 
theorie des fonctions analytiques. II y a la un ordre immense de re- 
chercbes egalement interessantes pour la theorie pure et pour les appli- 
cations de I'analyse. Sans meme aborder de questions entierement 
nouvelles, que de points seraient a reprendre dans les travaux celebres 
des physiciens geometres de la premiere moitie du siecle, de Fourier, 
de Poisson, de Cauchy meme, si on voulait y apporter la rigueur que 
Ton exige aujourd'hui en mathematiques. 

Je dois ajouter d'ailleurs, comme transition entre les deux directions 
relatives aux generalites sur les equations aux derivees partielles, qu'il 
existe des classes tres etendues d'equations dont toutes les integrales sont 
analytiques. Citons les equations lineaires d'ordre n a deux variables 
independantes : dans une region du plan ou toutes les caracteristiques 
sont imaginaires, toute integrale bien determinee et continue ainsi que 
ses derivees partielles jusqu'a I'ordre n est necessairement analytique. 
II y a aussi de nombreuses equations non lineaires ayant toutes leurs 
integrales analytiques. 

Je viens de parler des caracteristiques d'une equation ; c'est la un 
sujet en connexion etroite avec les tbeoremes generaux d'existence qui 
viennent de nous occuper. Les caracteristiques sont certaines multipli- 
cites jouissant de proprietes particulieres relativement a une equation 
donnee, multiplicites singulieres en ce qu'elles ne definissent pas une 
integrale contrairement a ce qui arrive en general pour les multiplicites 
contenant les memes elements. Tandis que la notion de caracteristiques 



Seconde Conference. 231 

est aujourd'hui tres nette pour les equations ou systemes d'equations a 
deux variables independantes, elle a encore besoin d'etre approfondie dans 
le cas de plus de deux variables. 

in. 

Si, quittant les generalites relatives a I'existence des integrales, nous 
voulons parler de la recherche effective des integrales et de I'etude 
d'equations particulieres, I'embarras est grand de tenter des classifica- 
tions dans un ensemble considerable de travaux, et nous sentons combien 
nos classements sont toujours defectueux par quelque endroit. Peut-etre 
pourrait-on tout d'abord distinguer I'ancienne ecole mathematique, et le 
mot "aMCj'ewMe" ne veut pas dire qu'elle ne continue pas a prosperer. 
C'est I'Ecole d'Euler, de Lagrange, de Monge dans son immortel ouvrage 
sur les applications de I'analyse a la geometrie, d' Ampere dans son celebre 
memoire de 1817 sur les equations aux differences partielles. En France, 
cette ecole des analystes geometres pour qui les problemes de geometrie 
infinitesimale sont I'occasion de belles recherches analytiques, a pour chef 
M. Darboux. Ses Legons sur la Th^orie des surfaces sont aujourd'hui 
un livre classique qui a rappele I'attention sur des questions quelque 
temps negligees. Relativement a I'integration effective des equations du 
second ordre, pendant de longues annees apres la publication du memoire 
d' Ampere, il n'avait ete rien ajoute d'essentiel a la theorie developpee par 
le grand geometre. En 1870, M. Darboux publia un memoire renfermant 
des vues profondes et originales qui est fondamental dans I'histoire de 
cette theorie. Depuis cette epoque, divers geometres ont developpe des 
methodes plus ou moins analogues. M. Goursat vient de rassembler dans 
un ouvrage considerable les methodes proposees, en y ajoutant ses decou- 
vertes personnelles sur ces questions difficiles. On pent caracteriser 
toutes ces recherches, en disant qu'on s'y propose de trouver explicite- 
ment des integrales avec le plus grand degre possible d'indetermination. 
Quelquefois, les methodes sont des indications de marche a suivre quand 
telle circonstance heureuse se presente, et on cherche des classes d'equa- 
tions pour lesquelles il en soit ainsi ; dans d'autres cas, on renonce au 
moins temporairement a I'integration complete, et on recherche des solu- 
tions de plus en plus etendues au moyen de transformations convenables 
comme, par exemple, celles de M. Bianchi pour I'equation des surfaces a 
courbure constante. 

Les idees du grand geometre norvegien, Sophus Lie, dont la science 



232 Emile Picard : 

deplore la perte recente, ont exerce aussi depuis vingt ans une grande 
influence dans I'etude des equations differentielles sous le point de vue 
qui nous occupe en ce moment. La theorie des groupes de transforma- 
tions, une des plus belles creations mathematiques de ce siecle, est venue 
apporter un element incomparable de classification ; elle a permis de faire 
une vaste synthese en donnant une origine commune a des notions eparses 
qui paraissaient sans liens. 

Je disais tout a I'heure que nos classifications se plient difficilement a 
la complexite des choses. Certains problemes se trouvent a un confluent, 
ou se rencontrent I'ancienne Ecole de Monge et d' Ampere et I'Ecole plus 
recente qui se rattache a la theorie moderne des fonctions. Monge avait 
integre I'equation des surfaces minima, et c'est la un de ses titres de 
gloire. Ses formules ont ete transformees par Weierstrass, et alors a 
apparu le lien entre la theorie des fonctions d'une variable complexe et la 
theorie des surfaces minima. Un probleme appelle vivement Tattention 
dans cette theorie : c'est le probleme de Plateau relatif aux surfaces 
minima passant par un contour donne. II a ete resolu seulement dans 
des cas tres speciaux ; je crois qu'en exercant la sagacite des analystes il 
sera quelque jour roccasion de progres importants dans I'analyse generale. 



J'ai surtout parle jusqu'ici des equations aux derivees partielles. La 
theorie des equations differentielles ordinaires est plus speciale, d'autant 
que quelques uns ont une tendance a la regarder comme un chapitre de la 
theorie des fonctions analytiques. Apres les remarques que j'ai faites 
hier, je n'ai pas besoin d'ajouter que ce n'est pas la mon opinion ; je vous 
ai indique plusieurs problemes qui ne relevent en rien de la theorie des 
fonctions analytiques, et il me suffira de citer encore 1' extension des idees 
de Galois aux equations differentielles. Ceci dit, il n'est pas douteux que 
les progres de la theorie des fonctions analytiques ont exerce la plus 
heureuse influence sur certains points de la theorie des equations diffe- 
rentielles ordinaires. Je ne ferai que rappeler le memoire celebre de 
Puiseux sur les fonctions algebriques, dans lequel etudiant a un point 
de nouveau les plus simples des equations differentielles a savoir les 
quadratures, il revele I'origine de la periodicite des integrales de differen- 
tielles algebriques. Les recherches de Briot et Bouquet ne sont pas 
moins classiques ; les auteurs y etudient les circonstances singulieres qui 
peuvent se presenter dans une equation du premier ordre quand le coeffi- 



Seconds Conference. 233 

cient differentiel devient infini ou indetermine. II faut se reporter a pres 
de cinquante aus en arriere pour bien juger ce memoire, ou pour la 
premiere fois est mis en evidence le role des points singuliers dans I'etude 
des fonctions ; ces notions nous sont bien familieres aujourd'hui, mais 
nous ne devons pas oublier que ce sont les memoires de Puiseux et de 
Briot et Bouquet qui en ont montre la haute importance. II semble que 
le memoire de Briot et Bouquet aurait du etre immediatement I'origine 
de travaux dans la meme voie, mais bien des annees se passerent avant 
qu'il ne fut repris et complete. C'est en AUemagne, sous rinfluence de 
I'enseignement de Weierstrass que nous voyons d'abord reparaitre I'etude 
des singularites des equations diiferentielles, et cela pour les equations 
differentielles lineaires. II est vraiment curieux que Briot et Bouquet, 
apres avoir traite le cas plus difficile des singularites d'une equation non 
lineaire, fut-elle du premier ordre, n'aient pas songe a s'occuper des equa- 
tions lineaires, laissant a M. Fuchs I'honneur de fonder une theorie, dont 
I'illustre geometre allemand a fait lui-meme des applications du plus 
haut interet, et qui a provoque un nombre immense de recherches. On 
remplirait des bibliotlieques avec les memoires composes depuis trente ans 
sur la theorie des equations lineaires. Je ne puis songer a voiis parler 
des nombreuses classes d'equations dont I'etude a ete faite. En restant 
dans les generalites, je rappelle seulement que I'etude des points singuliers 
presente une grande difference suivant que ce point singulier est regulier, 
comme dit M. Fuchs, ou presente les caracteres d'un point singulier 
essentiel. Ce dernier cas est de beaucoup plus difficile; M. Thome A 
forme des series satisfaisant formellement a I'equation, mais qui en general 
ne sont pas convergentes. Remarquons a ce propos que Briot et Bouquet 
ont les premiers montre qu'une equation differentielle pouvait conduire a 
une serie en general divergente ; leur exemple bien simple est I'equation 

x^^ =ax-[-hy 
dx 

verifiee par une serie entiere dont le rayon de convergence est nul. Cette 
petite constatation a appele I'attention sur un fait d'une importance 
capitale, et qui ne se rencontre qiie trop frequemment dans les applica- 
tions; les developpements purement formels sont nombreux en meca- 
nique analytique et mecanique celeste, ou ils font le desespoir des 
geometres. Pour les equations lineaires, ces developpement ont un 
certain interet, comme I'a montre M. Poincare, au point de vue de la 



234 Emile Picard. 

representation asymptotique des integrales. On pent d'ailleurs obtenir 
et de bien des manieres, une representation analytique des integrales 
autour du point singulier. Je dois enfin mentionner, relativement aux 
points singuliers irreguliers, les recherches de M. H. von Koch qui a tire 
tres heureusement parti dans cette question des resultats obtenus sur les 
determinants d'ordre infini. 

Revenons aux equations du premier ordre. Briot et Bouquet ont 
surtout etudie les singularites en faisant les reductions au type 

oil / est holomorphe et s'annule pour z = 0, y = 0, et leurs recberclies 
ont ete depuis completees par la connaissance de la forme analytique des 
integrales au voisinage du point singulier. Le cas plus complique de 
r equation 

x^^ = f(x,y^ (m>2-) (1) 

n'ayait fait jusqu'a ces derniers temps I'objet d'aucune recberclie depuis 
les quelques lignes que lui avaient consacrees Briot et Bouquet. Cette 
etude vient d'etre reprise simultanement par M. Horn et par M. Bendix- 
son. Ces auteurs se servent d'une methode convenable d'approximations 
successives dont j'indiquerai le principe. Nous supposons expressement 
que X reste reel et se rapproche de zero par valeurs positives, et posons 

f {x, y-) = hy + F (x, y') 

F ne contenant pas de terme du premier degre en y independant de x. 
Si la partie reelle de h est positive, I'equation precedente a une infinite 
d'integrales tendant vers zero en meme temps que x, et elle n'en a qu'une 
quand la partie reelle de h est negative. Les deux cas peuvent etre 
traites en faisant les approximation successives 

x-^=hy, 
x'^-^^hy^ + Fix, y{) 



'^ = iy,. + FCx,y„_{) 



Seconde Conference. 235 

et on obtient ainsi une representation analytique des integrales (ou de 
I'integrale). II existe un developpement 

a^x + a^ + ••• + a^a;" + ••• 

satisfaisant formellement a I'equation (1), mais dont le rayon de conver- 
gence est nul en general ; c'est la generalisation de la remarque de Briot 
et Bouquet, et on peut ajouter que la derivee d'ordre n de toutes les 
integrales considerees tend vers 1 • 2 ••• w • a„, quand x tend vers zero. 
De plus, quand il y a une infinite d'integrales tendant vers zero en meme 
temps, elles sont toutes representees asymptotiquement par le meme 
developpement, ce qui est evidemment defavorable pour I'interet que 
peut presenter une telle representation asymptotique. Les methodes 
precedentes sont d'ailleurs susceptibles de s'etendre a un systeme d'equa- 
tions differentielles. Je ferai encore une remarque importante sur 
I'equation (1) ; le cas ou la partie reelle de b est nuUe echappe complete- 
ment a la methode. L' equation a en general des integrales qui ne ten- 
dent vers aucune limite pour a; = 0. On se trouve alors, sur un exemple 
tres simple, en presence des difficultes considerables que Ton rencontre 
dans plusieurs questions de mecanique analytique; c'est en vain que 
Ton a tente jusqu'ici de proceder par approximations successives con- 
vergentes et les developpements essayes sont en general divergents. 

Quoi qu'il en soit des difficultes restant encore a surmonter, des 
progres serieux ont ete realises ces dernieres annees dans I'etude des 
integrales des equations non lineaires au voisinage des points singuliers 
mis en evidence par la forme meme de I'equation differentielle. De tels 
points singuliers sont les sQuls que puissent avoir les integrales quand 
il s'agit d'une equation lineaire, mais il en est autrement pour les equa- 
tions non lineaires. En dehors des points singuliers, qui sont apparents 
sur I'equation, il peut y en avoir d'autres variables d'une integrale a 
I'autre. Les equations du premier ordre ne presentaient pas a cet egard 
de bien grandes difficultes. En se bornant aux equations differentielles 
algebriques, tous les points singuliers qui ne sont pas apparents ne 
peuvent etre que des points critiques algebriques. Des exemples simples 
montraient que pour les equations d'ordre superieur au premier, il n'en 
etait plus de meme et qu'il pouvait y avoir des points essentiels mobiles; 
I'attention avait ete appelee sur ce point quand on avait voulu etendre 
aux equations du second ordre a points critiques fixes les methodes qui 
avaient reussi pour les equations du premier ordre possedant la meme 



236 Emile Picard: 

propriete. La difficulte signalee restait entiere, quand M. Painleve est 
venu faire une importante distinction et signaler un fait inattendu. Les 
points singuliers mobiles peuvent se partager en deux classes, les points 
singuliers algebriques ou transcendants pour lesquels I'integrale et ses 
derivees acquierent une valeur determinee finie ou infinie, et les points 
singuliers essentiels. M. Painleve a etabli que, dans les equations diffe- 
rentielles algebriques, le cas ou les points singuliers essentiels sont 
mobiles est un cas exceptionnel. Ces equations se trouvent ainsi par- 
tagees en deux classes, une classe generale pour laquelle I'integrale 
generale n'a pas de singularites essentielles mobiles, et une classe singu- 
liere. L'interet de cette distinction est tres grand dans I'etude de 
quelques classes particulieres d'equations differentielles. 

V. 

Arretons nous specialement sur le cas ou la variable et les fonctions 
restent reelles; c'est le cas interessant pour les applications. Nous 
designerons par t la variable independante qui sera, si Ton veut, le 
temps. Pour etudier quantitativement les fonctions definies par les 
equations differentielles, c'est a dire pour pouvoir evaluer numerique- 
ment les valeurs de ces fonctions, on doit desirer d'avoir des represen- 
tations de celles-ci permettant de les calculer pour un intervalle de temps 
aussi grand que possible. II y a des classes assez etendues d'equations 
differentielles, d'apres la forme desquelles on est assure d'obtenir des 
developpements valables pour toute valeur de t. Un cas tres simple 
est celui des equations 

^=m^yvy.^-^yn) (t = i,2, ...,n). 

On suppose que les fonctions / restent continues pour toutes les 
valeurs reelles et finies de t et des y, et que de plus les derivees -j^ 
restent en valeurs absolues moindres qu'un nombre fixe. La methode 
de Cauchy ou la methode des approximations successives donne pour 
les y des developpements valables pour toute valeur du temps. 

En supposant que les fonctions / soient analytiques et regulieres 
pour toute valeur reelle finie ou infinie de t et des y, on pent proceder 
autrement dans la recherche d'un developpement valable pour toute 
valeur du temps. II suffit de faire, avec M. Poincare, une representa- 
tion conforme, sur un cercle situe dans le plan d'une variable z, d'une 



Seconde Conference. 23'7 

bande tres petite dans le plan de la variable t (supposes un instant 
complexe), bande parallele a I'axe reel, ce qui revient a poser 

z = • 

e'-' + l 

On pent ici proceder encore d'une autre maniere en se rappelant que 
M. Painleve a etabli que toute fonetion holomorphe d'une variable reelle 
dans uu intervalle peut etre developpee en une serie de polynomes dont 
les coefficients dependent lineairement des valeurs de la fonetion et de 
ses derivees pour une valeur particuliere t = i,,. 

II y a des cas ou I'equation ne rentre pas dans les types precedents, 
et ou Ton sera cependant, au moins pour certaines integrales, assure de 
la possibilite d'un developpement toujours valable. Je citerai comme 
premier exemple les equations 



-1^ = — ax 
dt 



+-^(?^'^) l = -^^ + ^(?^'^) 



ou a et i sont deux constantes positives ; f et F designe des series holo- 
morpbes en -, x et «/, et ne renfermant pas de termes constants et de 
termes du premier degre en x et y. II est aise d'etablir que, pour 
t= ti) suffisamment grand, les valeurs initiales etant suffisamment petites, 
les integrales correspondantes tendront vers zero pour ^ = oo. De tels 
exemples sont malheureusement tres rares ; on peut encore citer les 
problemes de mecanique ou il y a une fonetion des forces. Chacun salt 
que I'equilibre est stable, dans le voisinage d'une position ou la fonetion 
des forces est maxima, mais ce resultat classique provient de I'etude 
indirecte des equations differentielles ; le meme probleme nous montre 
vite combien une etude directe serait desirable, et combien de difficultes 
restent a vaincre. Ainsi, supposons qu'il n'y ait pas de fonetion de 
forces et bornons nous a un point materiel. Ecrivons les equations 

g=«^ + j^+... ^^a'x + h'y+... ^(2) 

ou les seconds membres sont des developpements suivant les puissances 
de z et ?/, et convergents pour x et y assez petits. Le point a;= 0, y =0 
correspond-il a une position d'equilibre stable ? II est impossible ac- 
tuellement de repondre a cette question. II y a peut-etre quelques 
mecaniciens qui croient que la nature de I'equilibre depend seulement 



238 Emile Picard: 

des termes du premier degre dans le second membra. Nous nous garde- 
rons bien de leur en vouloir, car c'etait au fond I'erreur de Lagrange, 
mais il est clair qu'en reduisant les equations a la partie lineaire, on pent 
avoir une solution stable qui cesse de I'etre quand on retablit les termes 
d'ordre superieur. Les equations (2) presentent une particularite curi- 
euse qui merite d'etre signalee. On peut se proposer de trouver une 
integrale premiere 

F etant en holomorphe en x, y, x\ y\ et commengant par des termes du 
second degre. Or on trouve une telle fonction F au point de vue formel, 
mais la serie ainsi obtenue ne converge pas en general. J'ajoute que, 
si la force dependait non seulement de la position du point mais de la 
vitesse, c'est-a-dire si dans (2) les seconds membres dependaient aussi 
de x' et y, la recherche de la fonction F ne pourrait plus generalement 
etre effectuee, mais il serait plus facile de repondre a la question relative 
a la stabilite. 

Quand on a aucune notion de la grandeur de I'intervalle pour lequel 
les fonctions definies par les equations differentielles sont continues, on 
peut cependant trouver des developpements valables pour tout le temps 
pendant lequel les fonctions resteront continues. J'ai dit tout a I'heure 
que Ton pouvait deduire de tels developpements de la methode classique 
de Cauchy ; c'est la un resultat interessant, mais malheureusement il 
n'a guere qu'un interet theorique, car il semble bien difficile de deduire 
de ces developpements quelques renseignements sur le champ ou les 
integrales restent continues. 

II y aura cependant des cas ou certaines proprietes auxiliaires des 
equations permettent d'avoir des renseignements sur le champ oii les 
integrales restent continues. Que I'on prenne, par exemple, les six 
equations classiques en p, q, r, y, y', y" relatives au mouvement d'un 
solide pesant suspendu par un point ; I'integrale des forces vives et 
I'integrale y'^, y'^, y"^ = const, permettent de reconnaitre que les six 
fonctions precedentes resteront finies pour toute valeur du temps, et 
nous sommes alors assure que pour ce probleme la methode de Cauchy 
donne des developpements valables pour toute valeur du temps. 



Seconde Conference. 239 

VI. 

A I'ordre d'idees qui nous occupe, se rattachent les travaux de M. 
Poincare sur les solutions periodiques, et sur les solutions asymptotiques. 
L'etude des solutions periodiques d'une equation differentielle presente 
un interet particulier. Je connais peu d'exemples oil on puisse trouver 
directement une solution periodique. Dans ses travaux sur ce sujet, M. 
Poincare procede par voie indirecte ; il profite de la presence d'une con- 
stante tres petite dans les equations, et il raisonne par continuite en par- 
tant d'une solution periodique pour la valeur zero de cette constante. II 
serait a desirer que Ton put penetrer par une autre voie dans l'etude des 
solutions periodiques. Quant aux solutions asymptotiques a une seule 
solution, leur etude resulte de developpements analytiques simples ; mais 
I'existenee dans certains cas particuliers de solutions doublement asymp- 
totiques, c'est a dire de solutions asymptotiques pour t = — ca k une 
solution periodique et de nouveau asymptotiques pour ^ = + co a cette 
meme solution etait extremement eachee, et leur decouverte a demande 
un effort considerable. 

L'etude des courbes dej&nies par les equations differentielles est sur- 
tout une etude qualitative. Si I'on considere d'abord une equation du 
premier ordre et du premier degre. 

^ = ^ (X et F polynomes en x et ?/) (2) 

l'etude des points singuliers generaux se deduit des resultats de Briot et 
Bouquet. Ces points se partagent en trois ty^jes, que M. Poincare ap- 
pelle des cols, des ncBuds et des foyers. Un point singulier d'une nature 
deja plus compliquee est fourni par ce que M. Poincare appelle un centre, 
qui en general presente de I'analogie avec les foyers mais autour duquel 
dans certains cas I'integrale constitue une courbe fermee. On a alors un 
exemple de solutions periodiques dont la periode depend des conditions 
initiales. Les travaux les plus recents sur les points singuliers de courbes 
integrales de I'equation (2) sont dus a M. Bendixson ; le savant geometre 
suedois a etabli en particulier que s'il existe pour I'equation (2) une 
courbe integrale allant a I'origine avec une tangente determinee, toutes 
les courbes integrales allant a I'origine y parviendront avec des tangentes 
determinees. 

L'etude des courbes integrales ne doit pas etre bornee au voisinage 
des points singuliers ; on doit cliercber a se rendre compte de leur forme 



240 Emile Picard: 

sur le plan tout entier ou sur la sphere en faisant une perspective. Si 
Ton chemine, pour I'equation (2), sur une courbe integrale, qu'arrivera- 
t-il ? Cette courbe pent etre fermee de telle sorte qu'on reviendra au 
point de depart ; elle peut aussi avoir un des foyers comme point asymp- 
tote. EUe peut avoir encore pour courbe asymptote une courbe fermee 
satisfaisant d'ailleurs a I'equation differentielle. Ces courbes fermees, que 
M. Poincare appelle cycles limites jouent un role capital, et c'est dans les 
cas ou il est possible de se rendre compte de leur position que la dis- 
cussion de I'equation peut etre faite d'une maniere complete. 

Pour les equations du premier ordre mais de degre superieur les dif- 
ficultes sont beaucoup plus grandes. L'etude des points singuliers ge- 
neraux a ete faite ; elle trouve en particulier son application dans des 
problemes comme celui des lignes de courbure d'une surface passant par 
un ombilic. L'etude des courbes dans tout le plan est singulierement 
compliquee par un fait qui ne pouvait se rencontrer pour les equations 
du premier degre. II peut arriver qu'une courbe integrale couvre une 
aire, c'est a dire puisse se rapprocher autant qu'on voudra d'un point 
arbitraire dans une aire. 

D'apres les difficultes que presentent encore les equations du premier 
ordre, il est clair que pour les equations d'ordre superieur au premier 
l'etude qualitative des iutegrales soUicitera longtemps encore I'effort des 
chercheurs. Au point de vue analytique, une circonstance importante est 
a noter. Tandis que pour le premier ordre, on peut tirer parti dans quel- 
ques cas comme celui des centres de certains developpements en serie, il 
arrive au contraire ici dans les cas correspondants que les developpements 
analogues sont purement formels ; nous en avons vu un exemple en par- 
lant tout a I'lieure de la stabilite de I'equilibre. Remarquons a ce propos 
que les questions d'instabilite sont beaucoup plus faciles a traiter que les 
questions de stabilite comme il resulte des interessantes recherches de M. 
Liapounoff. Quand il y a une fonction des forces I'equilibre est stable 
si, pour cette position, la fonction des forces est maxima. Quant aux 
positions d'equilibre pour lesquelles cette derniere condition n'est pas 
remplie, on les a toujours regardees comme instables, mais leur instabilite 
n'avait pas ete demontree. M. Liapounoff I'a etablie en particulier pour 
le cas que I'on peut appeler general ou la non existence du maximum de 
la fonction des forces se reconnait par les termes du second ordre. 

Je citerai seulement un exemple relatif aux courbes integrales d'une 
equation d'ordre superieur au premier. Dans un memoire recent, M. 



Troisieme Conference. 241 

Hadamard vient d'etudier les lignes geodesiques des surfaces a courbures 
opposees et a connexion multiple ayant un nombre limite de nappes in- 
finies. II etablit que les tangentes aux lignes geodesiques passant par un 
point de la surface, et restant a distance finie, forment un ensemble par- 
fait non continu. Ce resultat est interessant au point de vue de la dispo- 
sition des lignes geodesiques de la surface ; il montre qu'il existe des 
lignes geodesiques se rapprochant d'une geodesique fermee determinee, 
puis abandonnant celle-ci pour se rapprocher d'une autre, puis passant a 
une troisieme, et ainsi de suite indefiniment. II montre de plus que 
Failure des courbes integrales pent dependre dans certains cas, des pro- 
prietes discontinues je veux dire arithmetiques des constantes d'integra- 
tion. C'est sur cette idee que je veux m'arreter ; dans la tlieorie des 
equations differentielles comme en maintes parties des mathematiques, les 
recherches sont obligees de prendre un caractere arithmetique. C'est 
V arithmStisation des mathematiques dont parlait M. Klein dans un article 
recent. 

J'ai essaye, messieurs, en restant dans les generalites et sans prendre 
aucune classe particuliere d'equations, de faire une sorte de carte geogra- 
phique sommaire de la theorie des equations differentielles. Beaucoup 
de voies sont ouvertes et dans des directions tres variees ; sur plus d'un 
point, les questions sont seulement posees, mais elles paraissent bien 
posees ; et nous nous rendons compte, ce qui a son prix, de la nature des 
difficultes qu'il faudra vaincre. C'est une etroite alliance entre les dis- 
ciplines les plus diverses qui amenera maintenant de nouveaux progres. 
II n'est plus permis aujourd'hui au geometre inventeur d'etre I'homme 
d'un seul point de vue, et il faut nous resigner a de grandes complica- 
tions. C'est un privilege que les sciences mathematiques partageront 
probablement dans I'avenir avec d'autres sciences. Esperons seulement 
que des hommes de genie viendront, de loin en loin, donner au moins pour 
un temps I'illusion de la simplicite. 

Tkoisiemb Conference. 

Sur la Theorie des Fonetions Analitiques et sur quelques Fonctions SpSciales. 

La theorie des fonctions de variables complexes est de venue aujourd'hui 
une branche considerable de I'analyse mathematique. EUe doit son bril- 
lant essor a la decouverte de quelques propositions generales parmi les- 
quelles se trouvent au premier rang les theoremes de Cauchy sur les 



242 Emile Picard: 

integrales prises le long d'un contour. Ces lois generales des fonctions 
analytiques appliquees a des fonctions speciales donnent souvent avec 
facilite leurs principales proprietes. L'application de ces lois constitue 
une methode synthetique, et des resultats auxquels avaient conduit une 
longue serie de transformations de calculs apparaissent quelquefois avec 
une evidence intuitive. La theorie des fonctions elliptiques en offre un 
memorable exemple, et n'y a-t-il pas quelque cliose de merveilleux a 
integrer avec M. Hermite le long d'un parallelogramme de periodes 
et a obtenir ainsi d'un trait de plume les principales proprietes des 
fonctions doublement periodiques ? La faQon dont Riemann pose et 
resout dans sa dissertation inaugurale le problems des integrales abe- 
liennes n'est pas moins digne d'etre meditee comme exemple d'une 
methode synthetique dans la theorie des fonctions. 



II n'est plus douteux aujourd'hui que les principes essentiels qui sont 
a la base de la theorie n'aient ete connus de Gauss. On salt que celui-ci 
ne publia pas ses recherches sur ce sujet. On ne pent guere admettre 
qu'il n'en ait pas saisi la haute importance ; fidele a sa devise " pauca sed 
matura " il attendait sans doute de s'etre livre a une plus longue elabora- 
tion, quand Cauchy fit connaitre ses decouvertes. On doit done regarder 
Cauchy comme le veritable fondateur de la theorie appelee a un si grand 
avenir ; non pas certes qu'il I'ait presentee sous une forme didactique. 
Ouvrant des voies nouvelles, son esprit toujours en travail se souciait peu 
de donner a ses conceptions une forme parfaite. On suit le travail 
d'invention dans maintes publications de Cauchy, notamment quand on 
parcourt dans ses CEuvres Completes les notes innombrables extraites des 
Comptes-Rendus. Dans la theorie qui nous occupe, une place a part doit 
etre faite a I'idee fondamentale d'etendre la notion de I'integrale definie 
en faisant passer la variable par une succession de valeui's imaginaires ; 
cette conception a ete la source des plus belles decouvertes, et la represen- 
tation d'une fonction par une integrale le long d'un contour ferme gardera 
a jamais le nom d'integrale de Cauchy. 

Le point de depart de Riemann se rapproche beaucoup de celui de 
Cauchy ; il est tres philosophique de prendre comme base les deux equa- 
tions simultanees 

du _dv du _ _ dv 
dx by dy dx 



Troisieme Conference. 243 

et de reduire ainsi la theorie des fonctions d'une variable complexe a 
I'etude de ces deux equations simultanees aux derivees partielles. En 
meme temps apparaissent les liens entre cette etude et plusieurs questions 
de physique mathematique comme le mouvement permanent des fluides 
sur un plan et celui de I'electricite sur une plaque conductrice ; et tous 
ces problemes sont susceptibles d'etre generalises si au plan simple dans 
lequel se meut la variable (x, y) on substitue le plan multiple de Riemann. 
Les deux relations ecrites plus haut amenent a considerer I'equation Am= 0, 
equation qui contient toute la theorie des fonctions d'une variable com- 
plexe, et parmi les problemes qu'on peut se poser sur cette equation le 
plus celebre est celui de la determination d'une integrale par ses valeurs 
sur un contour ferme. Une application d'une autre nature coneerne la 
geometric ; je veux parler du probleme des cartes geographiques qui amene 
a la question de la representation conforme d'une aire sur une autre. 

Weierstrass a edifie la theorie des fonctions de variables complexes sur 
une autre base que Cauchy et Riemann, en partant des developpements en 
series entieres ; en France, ces developpements avaient ete aussi envisages 
par M. Meray qui n'avait pas connaissance des legons de Weierstrass. 
Le memoire publie en 1876 par I'illustre analyste de Berlin, qui a fait 
connaitre a un public plus etendu les resultats developpes depuis long- 
temps dans I'enseignement du maitre, a ete le point de depart d'un grand 
nombre de travaux sur la theorie des fonctions. Cauchy avait deja obtenu 
d'importants resultats sur le developpement en sommes ou en produits 
infinis de certaines categories de fonctions. II etait reserve a Weierstrass 
et a ses disciples de traiter ces questions dans toute leur generalite. La 
decomposition des fonctions entieres, c'est a dire des fonctions uniformes 
et continues dans tout le plan, en facteurs primaires est un des plus 
admirables theoremes de I'analyse moderne ; chacun de facteurs primaires 
est le produit d'un facteur lineaire par une exponentielle. Les developpe- 
ments des fonctions uniformes en sommes et en produits infinis ont fait 
ensuite I'objet d'un grand nombre de travaux parmi les quels il faut citer 
tout particulierement le memoire de Mittag-Leffler qui a aborde ces prob- 
lemes avec la plus grande generalite possible. Je rappellerai aussi un 
memoire de M. Runge auquel des recherches toutes recentes viennent de 
redonner de I'actualite, ou se trouve en particulier etabli que toute 
fonction holomorphe dans un domaine connexe peut dans ce domains 
etre developpee en une serie de polynomes. 

Cauchy et ses disciples frangais, en etudiant la theorie des fonctions 



244: Emile Picard: 

uniformes, n'aTaient pas penetre dans I'etude de ces points singuliers 
appeles aujourd'hui points singuliers essentiels, dont le point 2=0 pour 

la fonction e^ donne I'exemple le plus simple. La consideration des 
facteurs primaires permit a Weierstrass de montrer que dans le voisinage 
d'un point essentiel isole une fonction uniforme peut se mettre sous la 
forme d'un quotient de deux fonctions uniformes n'ayant pas de poles 
dans le voisinage de a ; Weierstrass montra aussi que dans le voisinage 
d'un tel point la fonction s'approche autant que Ton veut de toute valeur 
donnee. On a plus tard complete ce resultat, en etablissant que dans le 
voisinage d'un point singulier essentiel isole la fonction prend rigoureuse- 
ment une infinite de fois toute valeur donnee, une exception seulement 
etant possible pour deux valeurs particulieres au plus. La demonstra- 
tion de ce theoreme se deduit de la consideration d'une fonction pre- 
sentant precisement la propriete qu'on veut demontrer etre impossible ; 
cette fonction est la fonction modulaire de la theorie des fonctions 
elliptiques, mais ses points singuliers ne sont pas isoles. Un coroUaire 
du theoreme indique conduit a la proposition suivante relative aux fonc- 
tions entieres : si, pour une fonction entiere G-(z) il existe deux valeurs 
a et h telles que les deux equations Q-(z} = a et (r(s) = h aient seulement 
un nombre limite de racines, la fonction 6r(2) est uil polynome. 

De nombreuses tentatives ont ete faites pour demontrer directement 
les theoremes precedents sans recourir a la theorie des fonctions ellip- 
tiques. Pour le theoreme sur les fonctions entieres, M. Hadamard avait 

7»=cO 

reussi a I'etablir quand, la fonction entiere etant representee par ^^a^a;"', 

on a («;„)< r-, a etant positif. Plus recemment M. Borel est 

[1 • 2 ••• »i]° 

arrive a le demontrer pour toutes les fonctions entieres et meme a le 

generaliser considerablement. 

Les travaux de M. Hadamard et de M. Borel publies dans ces 

dernieres annees sont extremement remarquables. Dans ces recherches, 

une notion importante introduite par Laguerre, celle du genre d'une 

fonction entiere, joue un role capital ; ce qui fait I'iuteret de cette 

notion, c'est qu'elle est intimement liee a la distribution des racines 

de la fonction. M. Poincare avait fait le premier la remarque que 

le genre d'une fonction entiere est en relation etroite avec I'ordre de 

grandeur de la fonction pour les grandes valeurs de la variable. M. 

Hadamard a cherche une limite du srenre a I'aide des coefficients du 



Troisieme Conference. 245 

developpement, et il a ^tabli que si le coefficient de x'^ est moindre que 

-, la fonction est de genre U en designant par U +1 I'entier 

(1 • 2 ••• my 

immediatement superieur a X. II a reussi aussi a demontrer que, en 
designant par ^(m) une fonction croissant indefiniment avec m, si le 
coefficient a^ decroit plus vite que — la p^^^ racine a un module 

superieur a (1 — e)0(^) ou e est infiniment petit pour p = co . De ses 
resultats, M. Hadamard a fait une belle application a I'etude de la distri- 
bution des racines d'une fonction celebre consideree par Riemann dans son 
memoire sur les nombres premiers. 

Dans son travail sur les zeros des fonctions entieres, M. Borel a eu 
surtout pour objet la demonstration de I'impossibilite de certaines iden- 
tites. Soit /A(r) une fonction positive croissant indefiniment avec r. 
Designons par 6^,(2) une fonction entiere dont le module maximum pour 
(2) = r est inferieur a e"*''', et JB^Ca) une fonction entiere dont le module 
maximum est superieur a [/t(?')]'"^% a etant positif ; I'identite 

ne peut avoir lieu que si tous les G sont identiquement nuls. En particu- 
lier pour w = 2, une pareille identite ne peut exister, Ctq etant une 
constante, (r^ et G-r^ des polynomes : c'est le theoreme enonce plus haut sur 
les fonctions entieres. 

Apres ces resultats sur les fonctions holomorphes dans tout le plan, 
revenons aux series entieres dont le rayon de convergence est fini. Une 
telle serie donne, pour employer le langage de Weierstrass, un element de 
fonction, en supposant bien entendu que le rayon de convergence n'est 
pas nul. L'extension analytique d'un tel element joue un role capital 
dans la theorie de Weierstrass ; il est dans cette etude du plus haut 
interet d'avoir des renseignements sur les singularites de la fonction sur 
le cercle de convergence. Le memoire de M. Darboux sur I'approxima- 
tion des fonctions de tres grand nombres, les reclierches plus recentes de 
M. Hadamard, de M. Borel et de M. Fabry ont conduit a des resultats 
d'un haut interet. Je ne veux signaler qu'une consequence curieuse, 
entrevue deja par M. Pringsheim : c'est qu'une serie entiere a en general 
son cercle de convergence comme coupure. On salt que Weierstrass a le 
premier indique un exemple d'un serie entiere ne pouvant etre prolongee 
analytiquement au dela de son cercle de convergence, et cet exemple 



246 Emile Picard: 

detourne provenait de la theorie des fonctions elliptiques. II est vrai- 
ment singulier que Ton ait eu autrefois quelques difficultes pour trouver 
des exemples de ce que Ton doit considerer maintenant comme la circon- 
stance la plus frequente. 

Parmi les methodes proposees pour I'etude de la serie prolongee au 
dela de son cercle de convergence, il en est deux qui sont particuliere- 
ment simples. La premiere, employee par M. E. Lindeloff repose sur la 
theorie de la representation conforme ; la seconde utilise la notion de 
serie divergente sommable resultant des travaux de M. Borel. Cette 
notion semble devoir jouer dans plusieurs questions d'analyse un role 
important. J'en indiquerai en deux mots le principe. Soit une serie, 
Mq +«!+••• Mn + ■■■ ; on lui associe la fonction de a: 

M(cf) = Mo + wjffl + j2-^ + • • • + j-T^r;:^ + - 

L'expression 



■■ Cu(^a)e 



peut avoir un sens quand la serie initiale est divergente ; on la regarde 
alors comme la limite de la serie. En appliquant cette notion a la pro- 
gression geometrique qui represente , et en se servant de I'integrale 

de Cauchy, on est alors conduit a une expression analytique qui dans bien 
des cas represente la fonction dans une aire exterieure au cercle de con- 
vergence. 

Je ne puis songer a rappeler, ne fut-ce que d'un mot, les etudes les plus 
importantes faites tout recemment sur le prolongement analytique. Arre- 
tons nous seulement sur un resultat que vient de publier M. Mittag-Leffler. 
Considerons, avec I'eminent geometre suedois, un element de fonction dans 
son cercle de convergence, et sur chaque rayon suivons la fonction 
jusqu'a ce que nous rencontrions un point singulier, celui-ci pouvant 
d'ailleurs etre a I'infini. On ne garde sur chaque rayon que la portion 
comprise entre le centre et le premier point singulier, et on obtient ainsi 
une aire que M. Mittag-Leffler appelle Vetoile correspondant a I'element 
de fonction. II montre qu'on peut obtenir une representation de la fonc- 
tion dans toute I'etoile, sous la forme d'une serie ayant pour termes des 
polynomes en x dont les coefficients sont lineaires par rapport aux coeffi- 
cients du developpement initial ; de cette fagon, quand on a en un point 
la valeur d'une fonction analytique et de toutes ses derivees, on peut 



Troisieme ConfSrence. 247 

obtenir a I'aide de ces seules donnees une representation de la fonction 
valable dans toute une etoile. Ce resultat pourra peut-etre avoir un cer- 
tain interet pour la theorie des equations differentielles ; il faut toutefois 
observer que dans ce cas la methode de Cauchy, comme nous I'avons dit 
hier, conduit au meme resultat. Ainsi les series considerees hier (page 
18), constituent des developpements valables dans une etoile. 

Nous avons, dans ce qui precede, considere un element de fonction, c'est 

a dire que la serie , , , „ , ^^N 

^ aQ + a-jX+ ••• + a^^x"^ + ■•• (1) 

avait un rayon de convergence different de zero. Si la serie precedente 
ne converge que pour x = 0, elle ne represente rien et il semble qu'il n'y 
ait aucun probleme a se poser a son sujet. Cependant nous avons donne 
hier des exemples d'equations differentielles conduisant a de tels developpe- 
ments; la derivee d'un ordre quelconque m de certaines integrales dans 
un certain angle ayant I'origine pour sommet tend vers 1 • 2 •••m • a„ quand 
X tend vers zero a I'interieur de Tangle convenable A. Ces conditions re- 
latives aux valeurs des derivees ne peuvent manifestement determiner une 
seule fonction dans Tangle A pres de I'origine, car on pent a une pre- 
miere fonction ajouter une exponentielle de la forme e""^" (a etant convena- 
blement choisie) dont toutes les derivees sont nuUes a I'origine ; mais, en 
appliquant sa methode de sommation des series divergentes, M. Borel est 
conduit a imposer une condition supplementaire et a obtenir alors, dans des 
cas etendus, une fonction unique determines par la serie divergente (1). 



Les divers travaux que je viens de rappeler montrent avec quelle 
activite les analystes se sont occupes dans ces derniers temps des gene- 
ralites concernant les fonctions analytiques d'une variable. La theorie 
geuerale des fonctions de plusieurs variables avance beaucoup moins 
rapidement ; les questions qui se posent ici sont beaucoup plus dif&ciles, 
tant en elles-memes que par le defaut d'une representation qui fasse 
image. Nous suivons une variable complexe sur son plan, mais avec 
deux variables complexes nous nous trouvons dans un espace a quatre 
dimensions, ori de plus les diverses coordonnees ne se presentent pas 
symetriquement. Au lieu de deux equations, nous avons quatre equa- 
tions aux derives partielles auxquelles doivent satisfaire deux fonctions 
de quatre variables. L'elimination d'une des fonctions conduit pour 
Tautre a un systeme de quatre equations aux derivees partielles qui 



248 Emile Picard: 

remplace I'equation cle Laplace, mais qui n'a pas ete etudie directement 
comme cette derniere equation. II semble qu'on ne puisse pour ce sys- 
teme se poser aucun probleme analogue a celui de Dirichlet et de Rie- 
mann ; nous ne trouvons ici aucune analogic entre le cas d'une variable 
et celui de deux variables. 

A un autre point de vue, le developpement de Taylor a deux variables 
pent bien servir a definir un element de fonction, mais nous n'avons rien 
d'analogue au cercle de convergence. Que sent les regions de conver- 
gence pour un tel developpement? II faudrait considerer des surfaces 
dans I'hyperespace a quatre dimensions ; aucune regie n'etant connue 
a cet egard, on se borne a considerer deux cercles assez petits dans les 
plans respectifs des deux variables, cercles a I'interieur desquels la serie 
est convergente. 

Les theoremes generaux sur les fonctions analytiques de deux 
variables complexes sont peu nombreux. Une remarque souvent utile 
a ete faite il y a longtemps par Weierstrass ; elle a en quelque sorte 
pour objet de mettre en evidence, dans une fonction de n variables 
holomorpbes autour de 0;^= 0, •••, a;„= 0, et s'annulant pour ces valeurs 
des variables, la partie de la fonction qui s'annule. Weierstrass montre 
que autour de a^j = ••• = a;„ = la fonction pent se mettre sous la forme 
d'un produit de deux facteurs holomorpbes, dont I'un ne s'annule pas 
a I'origine et dont I'autre est un polynome par rapport a I'une des 
variables. Une autre proposition d'une demonstration delicate est due 
a M. Poincare et a pour objet de generaliser le theoreme de Weierstrass 
relatif aux fonctions uniformes d'une variable n'ayant a distance finie 
que des poles, fonctions qui peuvent se mettre sous la forme d'un quotient 
de deux fonctions entieres. Pareillement une fonction de deux variables 
qui, pour toutes les valeurs finies des variables presente le caractere d'une 
fonction rationnelle pent etre mise sous la forme d'un quotient de deux fonc- 
tions entieres. Ce beau theoreme a ete etendu par M. Cousin, qui a suivi 
une toute autre voie, aux fonctions d'un nombre quelconque de variables. 

On doit encore a M. Poincare un resultat bien saillant : je veux 
parler de I'extension aux integrales doubles du theoreme fondamental 
de Cauchy relatif aux integrales simples prises le long d'un contour. II 
n'y a pas de difficulte a definir une integrale double d'une fonction 
F(x, y) de deux variables complexes 2; et «/ 



J*J*#(a;, y~)dxdy 



Troisieme Conference. 249 

sur un continuum a deux dimensions situe dans I'liyperespace a quatre 
dimensions qui correspond aux deux variables complexes. Si le con- 
tinuum est ferme, et qu'on puisse le reduire a une ligne oii a un point 
sans que F cesse d'etre continue, I'integrale sera nulle. Ce resultat 
conduit a poser un grand nombre de questions. Si F est une fonction 
rationelle, il y a lieu de considerer les residus de I'integrale double ; ces 
residus s'expriment par des periodes d'integrales abeliennes ordinaires. 
Si F est une fonction algebrique de x et ^, on aura a envisager les 
periodes de I'integrale double, et on voit s'ouvrir un vaste champ de 
recherches. On s'apergoit d'ailleurs bien vite que si certaines analogies 
subsistent avec le cas d'une variable, il en est beaucoup d'autres qui 
disparaissent entierement. Des integrales le long d'un contour ont 
donne a Cauchy le nombre des racines d'une equation contenues dans 
ce contour, mais dans la question correspondante du nombre des racines 
communes a deux equations simultanees, les integrales doubles n'ont 
aucun role a jouer ; ce sont des integrales triples etendues a un certain 
continuum a trois dimensions qui interviennent dans cette recherche. 

Je parlais tout a I'heure de la dissymetrie qui se presente au point 
de vue reel dans la theorie des fonctions de deux variables complexes. 
II etait interessant de rechercher si il n'est pas possible de generaliser 
les deux equations aux derivees partielles de la theorie d'une fonction 
d'une variable. Le probleme est evidemment indetermine ; tout depend . 
de la propriete de ces equations sur laquelle on porte specialement son 
attention. On pent se placer au point de vue suivant : rechercher tons 
les systemes d' equations aux derivees partielles relatifs a n fonctions de 
n variables independantes et telles que, si u^, Mji •"'^m ^t Vj, v^, ••■v„ de- 
signent deux solutions quelconques, les v considerees comme fonctions 
des u satisfassent au meme systeme. Cette propriete appartient evidem- 

, ' ,■ du dv du dv ^ i i i 

ment aux deux equations -r— =t— , t— = — t-. -La recherche de ces sys- 
ox ay ay ax •' 

temes peut se faire d'une maniere reguliere, et pent se deduire de la 

connaissance des certains groupes d'ordre fini ; ainsi tous les systemes 

du type precedent d'equations aux derivees partielles du premier ordre 

pourront etre obtenus a I'aide des groupes lineaires et homogenes a n 

variables. II est possible que, parmi tous ces systemes, il en est qui 

presentent quelque interet particulier, et avec lesquels on puisse edifier 

une theorie plus ou moins analogue a la theorie d'une fonction d'une 

variable complexe. Le cas de w = 3 ne donne rien d'interessant ; pour 



250 Emile Picard: 

71=4:, on pourrait prendre d'abord le groupe lineaire qui donne naissance 
aux quaternions, il lui correspond un systeme d'equations differentielles 
qui presente peut-etre quelque interet. 

Cette extension de la theorie des fonctions d'une variable complexe 
n'est pas la seule qui ait ete proposee. M. Volterra a cherche dans una 
autre voie en considerant des fonctions de ligne, ce qui I'a conduit a 
d'interessantes relations differentielles et a quelques problemes analogues 
a ceux de Dirichlet. L'avenir dira si ces extensions sont simplement des 
curiosites ou si elles presentent quelque interet general. 



Quittons maintenant les generalites et jetons un coup d'ceil sur 
quelques fonctions speciales. II n'en est pas qui aient ete plus etudiees 
que les fonctions algebriques d'une variable ; c'est en faisant leur etude 
que Puiseux, dans un memoire reste celebre, a appele I'attention sur 
I'interet que presentait la consideration de la variable complexe. On 
a quelque peine a se representer qu'il a paru merveilleux que V^ et — 'Vx 
puissent etre considerees comme deux determinations d'une meme fone- 
tion ; c'est dans ce memoire aussi qu'apparait pour la premiere f ois 
I'origine de la periodicite. 

La theorie des fonctions algebriques est devenue un confluent ou se 
rencontrent les notions les plus diverses ; chacun, suivant ses gouts, pent 
y trouver les points de vue qu'il prefere. Avec les metliodes de Weier- 
strass, nous trouvons la precision extreme qui caracterise son ecole, et le 
souci constant de n'introduire aucune consideration etrangere a la theorie 
des fonctions fut ce au prix de detours longs et penibles. Celui qui aime 
le langage et les formes de raisonnement de la geometric analytique 
suivra Brill et Noether dans leur theorie si feconde des groupes de 
points. Ceux enfin qui recherchent les grands horizons auront plaisir 
a lire Riemann qui, avec la merveilleuse conception de la surface qui porte 
son nom, rend, pour ainsi dire, intuitifs les points les plus delicats de la 
theorie. Ce serait d'ailleurs une vue etroite que de regarder seulement 
la belle conception de Riemann comme une methode simplicative. Pour 
Riemann, le point essentiel est dans la conception d priori de la surface 
connexe, formee d'un nombre limite de feuillets, et dans le fait qu'a une 
telle surface congue dans toute sa generalite correspond une classe de 
courbes algebriques. De plus, on pent envisager des surfaces de Riemann 
a un nombre infini de feuillets, et les travaux de Poincare ont montre le 



Troisieme Conference. 251 

role utile qu'elles peuvent jouer dans I'etude des fonctions non uniformes. 
On salt aussi I'importance qu'avait pour Riemann le probleme de la repre- 
sentation conforme ; le cas de la representation conforme des aires a 
connexions multiples a ete traite par M. Schottky dans un tres beau 
memoire ou I'auteur se montre disciple de Weierstrass, mais qui se rat- 
tache naturellement a I'ordre d'idees de Riemann. A una aire plane 
percee de p trous, envisagee comme ayant une face superieure et une face 
inferieure correspond une courbe algebrique de genre p ; la question de 
la representation conforme de deux aires revient alors a la correspondance 
entre les points de deux courbes algebriques. 

Aux courbes algebriques se rattaclient des fonctions extremement re- 
marquables d'une variable ; ce sont les fonctions que M. Poincare appelle 
fuchsiennes et que M. Klein designe sous le nom de fonctions automorphes. 
Pour les courbes des genres zSro et un, on pent exprimer les coordonnees 
par des fonctions uniformes d'un parametre, meromorpbes dans tout 
le plan (fonctions rationnelles et fonctions doublement periodiques). 
II etait naturel de cbercher, pour les courbes de genre superieur a un, une 
representation parametrique par des fonctions uniformes. Des tentatives 
varices ont probablement ete faites pour resoudre cette question, en cher- 
chant a realiser cette expression par des transcendantes n'ayant que des 
poles a distance finie. De telles tentatives, on le salt aujourd'hui, ne 
pouvaient reussir, car on peut etablir que, entre deux fonctions uniformes 
dans le voisinage d'un point qui est pour chacune d'elles un point singulier 
essentiel isole, ne peut exister une relation algebrique de genre superieur 
a I'unite. Les transcendantes a employer sont d'une nature beaucoup 
plus compliquee ; les unes ont un cercle comme coupure au dela duquel 
elles ne peuvent etre prolongees analytiquement, les autres sont definies 
dans tout le plan, mais elles ont sur un cercle une infinite de points singu- 
liers essentiels formant, d'apres la denomination de M. Cantor, un ensem- 
ble parfait qui n'est pas continu. Les celebres memoires de M. Poincare 
sur les fonctions fuchsiennes et les belles recherches de M. Klein sur le 
meme sujet forment un des plus beaux chapitres ecrits dans ces vingt 
dernieres annees sur la theorie des fonctions. Les fonctions automorphes 
forment une generalisation extremement etendue et remarquable des fonc- 
tions modulaires etudiees par M. Hermite dans la theorie des fonctions 
elliptiques, et des fonctions considerees par M. Schwarz en faisant dans 
certains cas I'inversion du rapport de deux solutions de I'equation hyper- 
geometrique. Toute cette theorie est d'ailleurs etroitement liee a la 



252 Emile Picard: 

theorie des equations lineaires, et c'est un des resultats les plus saillants 
obtenus par M. Poincare qu'avec des transcendantes analogues aux fonc- 
tions fuchsiennes on puisse integrer les equations differentielles lineaires 
a coefficients algebriques n'ayant que des points singuliers reguliers (au 
sens de M. Fuchs). 

Parmi les transcendantes se rattachant aux fonctions algebriques 
citons encore les integrales de fonctions a multiplicateurs etudiees tout 
particulierement par M. Appell. Ce sont des fonctions n'ayant sur la 
surface de Riemann que des poles ou des points singuliers logaritbmiques, 
et dont toutes les determinations se deduisent de I'une d'entre elles par 
des substitutions de la forme (m, au + b'); elles generalisent par suite les 
integrales abeliennes pour lesquelles les a sont egaux a I'unite. Un beau 
resultat obtenu par M. Appell est que ces fonctions se presentent dans la 
recherche des coefficients des fonctions abeliennes de deux variables quand 
on les developpe en series trigonometriques. On a aussi recherche les cas 
ou I'inversion d'une integrale de fonction a multiplicateurs conduit a une 
fonction uniforme, mais la conclusion a ete negative, c'est a dire que dans 
ce cas la courbe algebrique est necessairement du genre zero ou du genre 
un, et la fonction uniforme obtenue se ramene ou des transcendantes 
connues. 

IV. 

Les equations differentielles forment une mine inepuisable pour ob- 
tenir des fonctions speciales. Les equations lineaires ont ainsi conduit a 
des fonctions jouissant de proprietes bien definies. Pour les equations 
non lineaires, M. Fuchs appela le premier I'attention sur les equations 
algebriques du premier ordre a points critiques fixes et montra comment 
on pent reconnaitre qu'on se trouve dans ce cas. M. Poincare fit voir 
ensuite qu'on pouvait ramener ce cas a des quadratures ou aux equations 
de Riccati. M. Painleve a etendu ces resultats en considerant les equa- 
tions du premier ordre dont les integrales n'ont qu'un nombre limite de 
valeurs autour de I'ensemble des points critiques mobiles. Une des con- 
clusions de ses recherches est que I'integrale, supposee transcendante, de 
toute equation algebrique du premier ordre qui satisfait a la condition 
precedente, est une fonction algebrique de I'integrale d'une equation de 
Riccati dont les coefficients dependent algebriquement de ceux de I'equa- 
tion donnee. On pent se proposer des problemes analogues pour les 
equations differentielles algebriques d'ordre superieur au premier. II se 
presente ici des difficultes considerables; I'une d'elles tient au fait suivant : 



Troisieme Conference. 253 

tandis que toute transformation biuniforme d'une courbe algebrique en 
elle-meme (avec singalarites isolees) est necessairement birationnelle, il 
pent arriver au contraire qu'une transformation biuniforme d'une surface 
algebrique en elle-meme ne soit pas birationnelle. Une seconde difficulte, 
non moins grave, consiste dans I'existence possible de singularites essen- 
tielles mobiles. J'ai indique hier la distinction faite a cet egard par M. 
Painleve entre la classe generale d'equations ne possedant pas de tels 
points et la classe singuliere. 

En cherchant a etendre aux equations du second ordre a points 
critiques fixes la methode qui avait reussi a M. Poincare pour les equa- 
tions du premier ordre jouissant de la meme propriete, on est arrete imme- 
diatement par la premiere difficulte signalee plus haut, et c'est seulement 
dans le cas ou I'integrale generale de I'equation est supposee dependre 
algebriquement des deux constantes d'integration que Ton pent pour- 
suivre I'etude sans de serieuses difficultes ; on retombe d'ailleurs sur des 
transcendantes deja connues. M. Painleve a fait une etude complete des 
autres cas qui peuvent se presenter ; I'integrale generale peut encore etre 
une fonction algebrique d'une seule des constantes, ou enfin dependre 
d'une maniere transcendante des deux constantes (de quelque fagon qu'on 
les choisisse). Ce dernier cas seul est irreductible aux transcendantes 
classiques, c'est a dire ne peut etre ramene aux quadratures et aux equa- 
tions lineaires. Ce cas se presente d'ailleurs effectivement, et M. Pain- 
leve a forme explicitement toutes les equations du second ordre de la 
forme 

y = -^(2/, «/', a;) 

on R est rationnel en y', algebrique en y et analytique en x ; elles se 
laissent ramener a douze types canoniques tres simples. J'indiquerai 
seulement deux de ces equations pour lesquelles I'integrale generale est 
uniforme, 

y" = 6y^ + X 

y" = 2y^ + xy -\- a (a = constante numerique) 

L'integrale generale de I'une et I'autre equation est une fonction uni- 
forme et meromorphe de x dans tout le plan, et cette integrale est une 
transcendante vraiment nouvelle. Ces exemples precis montrent com- 
bien M. Painleve a pousse jusqu'au bout ses profondes recherches. 

Je me bornerai a dire, relativement aux equations du troisieme ordre, 
que I'integrale generale peut avoir des lignes de points singuliers essen- 



254 Emile Picard: 

tiels. On en a facilement des exemples en considerant I'equation diffe- 
rentielle algebrique du troisieme ordre a laquelle satisfait une fonction 
automorphe d'une variable. 

V. 
Le champ des fonctions speciales de plusieurs variables complexes, 
dont I'etude a ete quelque pen approfondie, est assez limite. La theorie 
des fonctions abeliennes a fait I'objet d'un nombre considerable de tra- 
vaux qui sont trop classiques pour que je m'y arrete ici ; les memoires 
de Riemann et de Weierstrass, les etudes de M. Hermite sur la transfor- 
mation des fonctions abeliennes sont dans toutes les memoires. Apres 
les etudes faites sur les fonctions fucbsiennes d'une variable, il etait 
naturel de cbercher des transcendantes analogues pour le cas de deux 
variables ; on devait d'abord se demander s'il existe des groupes discon- 
tinus contenus dans le groupe lineaire a deux variables 

f a'u + h'v + c a"u + h"v + c"\ ^^ . 

\u,v; , . (Jl) 

\ au + ov + c au + ov + c J 

Un seul exemple d'un tel groupe, mais bien peu utile, s'offrait a 
I'esprit, celui du groupe a quatre periodes. Aucun exemple analogue 
au groupe modulaire ne se presentait, et il n'y avait rien a demander 
sur ce point a la theorie des fonctions abeliennes, au moins sous sa forme 
classique. Par quoi d'ailleurs se trouverait remplacee ici la condition 
imposee aux substitutions d'un groupe fuclisien, de conserver un certain 
cercle ? L'etude des formes quadratiques ternaires a indeterminees con- 
juguees vint permettre de former en grand nombre les exemples cher- 
chees. M. Hermite avait, il y a longtemps, montre I'interet au point 
de vue arithmetique des formes quadratiques binaires a indeterminees 
conjuguees ; les formes ternaires indefinies conduisirent a de nombreux 
groupes du type (1), discontinus a I'interieur d'une certaine hypersurface 
de I'espace a quatre dimensions. Cette surface remplace la circonference 
de la theorie des groupes fuchsiens. Les groupes du type precedent 
furent appelees groupes hyperfuehsiens ; on se rend aisement compte que 
leur recherche generale constitue, comme pour les groupes fuchsiens, un 
probleme uniquement d'ordre algebrique ; mais, toute representation 
geometrique faisant defaut, cette recherche directe serait tellement 
penible qu'elle est reellement impraticable. Aussi les exemples fournis 
par des considerations arithmetiques sont-ils extremement precieux. 



Troisieme Conference. 255 

Aux groupes hyperfuclisiens correspondent des fonctions unifornies 
restant invariables par les substitutions du groupe. 

Des exemples de fonctions hyperfuchsiennes d'une nature differente 
peuvent etre fournis par les series hypergeometriques de deux variables. 
Une telle serie, f onction de a; et y dependant de quatre parametres arbi- 
traires X, ix, Sj, et b^ satisfait a un systeme de trois equations lineaires aux 
derivees partielles du second ordre, ayant trois solutions communes 
lineairement independantes. Designant celles-ci par Wj, m^, ©g, on peut 
chercher dans quels cas les quotients 

ft>2_ Wg^ 

donnent pour x et y des fonctions uniformes de ii et v. Les conditions 
sont tres simples ; si on prend deux quelconques des quatre quantites 
\, fi, b^ et b^, soit, par exemple \ et 5^, la difference X + b^—l doit etre 
I'inverse d'un nombre entier positif, et pareillement si on prend trois 
quelconques de ces quantites, soit \, /m et S^, la difference 2 — X — fj, — b^ 
est encore egal a I'inverse d'un entier positif. Je citerai I'exemple 
\ = ;t4 = 6i = J2 = f pour lequel le polyedre f ondamental du groupe est 
tout entier a VintSrieur de I'hypersurface limite. 

On peut generaliser les fonctions fuchsiennes en considerant d'autres 
groupes discontinus que les groupes hyperfuchsiens. Une substitution 
birationnelle entre deux variables u et v n'est pas necessairement lineaire, 
et ce serait un probleme interessant mais difficile de former tons les 
groupes discontinus au moins dans une certaine region de I'hyperespace 
(u, V) de substitutions birationnelles. En dehors des groupes lineaires 
(hyperfuchsiens) on a seulement considere jusqu'ici les groupes formes 
de substitutions de la forme 



/ au + b\ / a'v + b' \ 



et des substitutions ou u est remplace par une fonction lineaire de v et 
inversement. Ce sont les groupes JiyperabSliens qui rentrent evidemment 
dans les types des substitutions quadratiques ; il y a dans ce cas deux 
domaines frontieres. II y aura sans doute des decouvertes interessantes 
a faire un jour dans le champ tres vaste des groupes discontinus de sub- 
stitutions birationnelles, et des fonctions correspondantes (dans le cas 
ou il en existera, comme il arrive pour les fonctions hyperfuchsiennes 
et hyperabeliennes) . 



256 Emile Picard: 



Nous avons rappele tout a I'heure le brillant dSveloppement de la 
theorie des fonctions algebriques d'une variable ; les progres ont ete 
beaucoup plus lents dans le champ de deux variables. C'est un sujet 
en pleine elaboration, et que Ton attaque de plusieurs cotes. Clebsch, 
se pla§ant au point de vue de la geometric analytique, signala le premier 
que, pour une surface algebrique de degre m, certaines surfaces d'ordre 
m — 4 devaient jouer le role que jouaient les adjoiutes d'ordxe m — 3 par 
rapport a une courbe de degre m. L'etude de ces surfaces d'ordre m — 4 
a ete reprise par M. Noether dans un memoire de grande importance. 
En se plagant au point de vue de la theorie des fonctions, voici I'origine 
de ces surfaces. Si on cherche les integrales doubles 

j jli(x, y, z)dx dy {fQc, y, z) = 0) 

restant toujours finies, integrales qu'on appelle les integrales doubles 
de premiere espece, on trouve qu'elles sont de la forme 



Sf 



Q(x, y, z)dx dy 



Q etant un polynome d'ordre m — 4. Le nombre pg de ces polynomes 
lineairement independants est ce que Ton appelle le genre giomHrique 
de la surface ; un pareil nombre est manifestement un invariant. Jus- 
qu'ici les analogies sont completes avec les courbes ; il y a des integrales 
doubles de premiere espece, comme il y a des integrales abeliennes de 
premiere espece. Mais une premiere difference va de suite se manifester. 
II faut calculer le nombre des arbitraires qui figurent dans les poly- 
nomes Q d'ordre m — 4 se comportant aux points multiples de la sur- 
face de telle maniere que I'integrale reste finie. Or on pent trouver par 
une formule precise le nombre des conditions ainsi entrainees, mais seule- 
ment pour un polynome d'un ordre suffisamment grand iV^; si done on 
fait dans cette formule iV= m — 4, il est possible que Ton trouve un 
nombre different de pg ; on designe le nombre que donne la formule a 
laquelle je fais allusion par p„, et on I'appelle le genre numerique de 
la surface. Le cas le plus general est celui ou p„=Pg\ quand il n'y 
a pas egalite, on a p„<Pg et la surface est dite irreguliere, tandis qu'elle 
est reguiiere si Pn= Pg- Cayley a le premier appele I'attention sur la 
curieuse circonstance qui precede ; Zeuthen et Noether etablirent ensuite 



Troisieme Conference. 257 

I'invariance du nombre p^, quand il n'est pas egal a pg. Les surfaces 
reglees offrent un exemple de surface irreguliere ; en designant par tt 
le genre d'une section plane arbitraire de la surface, on a 

i)„ = -7r, P,= 0. 

II y a pour une surface des polynomes adjoints d'ordre quelconque. 
On peut les definir facilement au point de vue transcendant. Si la surface 
a une position arbitraire par rapport aux axes, le polynome P(^x, y, z) 
sera un polynome adjoint si I'integrale double 



// 



'P(x, y, z) dx dy 



reste finie a distance finie ; la surface P = est une surface adjointe. 
M. Enriques a donne une tres remarquable interpretation geometrique 
de la difference pg — p„. Les adjointes d'ordre m — 4 + ?• decoupent sur 
une section plane determinee d'ailleurs arbitraire une serie lineaire de 
groupes de points qui peut n'etre pas complete si r est assez petit. De- 
signons par m^ le d6faut de cette serie lineaire par rapport a la serie com- 
plete ; on a 

r = \ 

la somme dans le second membre ne comprend qu'un nombre limite de 
termes, les w etant certainement nuls a partir d'une valeur assez grande 
de r. La formule precedente est fondamentale dans I'etude du genre 
numerique. 

Nous avons parle plus haut des integrales doubles de premiere espece 
relatives a une surface. On peut aussi developper une theorie des inte- 
grales doubles de seconde espece dont la definition est la suivante: ce sont 
les integrales qui deviennent infinies comme 



//i 



Vet V etant des fonctions rationnelles de x, y et z [/(x, y, s) = 0] . Le 
nombre des integrales distinctes de seconde espece, c'est a dire des 
integrales dont aucune combinaison lineaire n'est de la forme (a) est 
fini ; c'est un invariant de la surface. Mais il n'en est plus ici, comme 
dans le cas des courbes pour lesquelles le nombre des integrales abe- 
liennes distinctes de seconde espece etait egale k2p; le nouvel invariant 



258 Emile Picard: 

d'une classe de surfaces algebriques n'est pas lie au genre, soit geome- 
trique soit numerique. 

La consideration des integrales doubles ne se presente pas seule. On 
pent aussi envisager des integrales de diif erentielles totales de la forme 



i P (x, y, z)dx+ Q (a;, «/, z) dy 



ovl P Qt Q sont rationnelles en x, y et z, et il y a encore lieu de parler des 
integrales de premiere et de seconde espece. Mais ici de telles integrales 
n'existent pas en general, c'est a dire pour une surface prise arbitraire- 
ment, et c'est une question assez delicate que de reconnaitre si une surface 
possede des integrales de seconde espece en dehors des fonctions ration- 
nelles. 

Les questions de connexite presentent aussi un grand interet dans la 
theorie des fonctions algebriques de deux variables independantes, mais 
quelques precautions sont ici necessaires. Pour une surface determinee, 
et en procedant d'une maniere bien precisee, on pent obtenir deux nombres 
correspondant a la connexion lineaire et a la connexion a deux dimen- 
sions ; le premier p-^ est veritablement un invariant pour toute transfor- 
mation birationnelle, tandis que le second p^ pent etre influence par la 
presence de points fondamentaux dans la correspondance birationnelle. 
C'est un resultat remarquable que le nombre pj — 1 represente le nombre 
des integrales de differentielles totales distinctes de seconde espece rela- 
tives a la surface. Pour une surface arbitrairement choisie, il n'y a pas 
d'integrale de seconde espece et on a pj = 1. 

On voit que les points de vue de la geometric analytique, de la theorie 
des fonctions et de la geometric de situation se retrouvent aussi dans 
I'etude des surfaces algebriques, mais il faut se mefier des analogies avec 
la theorie des courbes. Tout, dans ce nouveau domaine, se presente 
d'une maniere plus compliquee. 

Voici encore un exemple de cette complexite. Les courbes dont le 
genre est nul ferment la classe tres restreinte des courbes unicursales. 
Au contraire les surfaces pour les quelles ^^ = sont extremement varices, 
et on pent dans ce cas considerer un nouvel invariant que M. Enriques a 
decouvert et qu'il appelle le higenre. On pent le definir aisement dans le 
cas ou la surface / de degre m n'a qu'une ligne double. On envisagera a 
cet effet le systeme des surfaces d'ordre 2 rni — 8 (ne se composant pas de 
/ et d'une surface d'ordre m — 8) ayant comme ligne double la courbe 



Troisieme Conference. 259 

double de /; le bigenre P est la dimension augmentee d'une unite de ce 
systeme. Cette notion a permis a M. Castelnuovo d'etablir un theoreme 
reellement merveilleux ; il s'agit des conditions necessaires et suffisantes 
pour qu'une surface soit unicursale. On pouvait penser que ces con- 
ditions seraient tres compliquees et non susceptibles d'une forme simple ; 
11 n'en est rien, elles se reduisent a p„ = 0, P = 0. Mais je dois m'arreter, 
me bornant a citer seulement le memoire si elegant de M. Humbert sur 
les surfaces byperelliptiques qui donnent un tres interessant exemple de 
surfaces irregulieres pour les quelles p„= — 1, tandis que pg=l. 

Nous avons, messieurs, jete un rapide coup d'oeil sur quelques unes 
des branches de la science mathematique. Vous avez pu vous apercevoir 
plus d'une fois de I'embarras dans lequel je me suis trouve, quand j'ai 
voulu, pour les necessites de mon exposition, faire une classification dans 
certaines theories. La penetration reciproque des diverses disciplines est 
aujourd'hui en effet un fait capital et sera de plus en plus la source d'im- 
portantes decouvertes. A cet egard, il y a une grande difference entre 
notre epoque et des temps un peu anterieurs. Nous avons peine aujour- 
d'hui a comprendre certaines histoires ou on voit des geom^tres mepriser 
des analystes et inversement ; nous sentons que I'ere des ecoles fermees et 
etroitement attachees a un seul point de vue est pour toujours terminee. 
II est bien vraisemblable que I'erudition jouera a I'avenir un plus grand 
role qu'autrefois en mathematiques. Les mathematiciens perdront peut- 
etre ce privilege de la pi'ecocite qui etonne tant de personnes ; ils se 
rapprocheront des physiciens et des naturalistes qui doivent en general 
commencer plus tard leurs travaux personnels. En terminant, je me 
permettrai de donner un conseil aux etudiants mathematiciens qui m'ont 
fait I'honneur de m'ecouter ; je leur recommanderai de ne pas se can- 
tonner trop tot dans des recherches speciales. II leur faut acquerir 
d'abord des vues generales sur les diverses parties de notre science, sans 
lesquelles leurs efforts risqueraient de rester steriles, et qui leur coiite- 
raient plus tard un bien plus grand effort. 




<^--i-j,-zx<-t.<Z.z-^ o6>T>-t>^i^.'»'»-— t^-^'-^'-^'-*'- 






UBEE DIE GRUNDPRINCIPIEN UND GEUND- 
GLEICHUNGEN DEE MECHANIK. 

Von Professor Ludwig Boltzmann. 

Eeste Voklesung. 

Die analytische Meclianik ist eine Wissenschaft, welche schon von 
ihrem Begriinder Newton mit solchem Scharfsinne und solcher Vollen- 
dung ausgearbeitet wurde wie es in dem gesammten Gebiete menscMichen 
Wissens fast ohne Beispiel dasteht. Die grossen Meister, welche auf 
Newton folgten, haben das von ihm errichtete Gebaude noch weiter 
gefestigt, und es hatte den Anschein, dass eine voUendetere und einheit- 
lichere Schopfung des Menschengeistes als die Grundlehren der Me- 
chanik, wie sie uns in den Werken von Lagrange, Laplace, Poisson, 
Hamilton etc. entgegentreten iiberhaupt nicht denkbar ware. Gerade 
die Begriindung der ersten Principien schien von diesen Forschern 
mit einem Scharfsinne und einer logischen Consequenz durchgefiihrt, die 
allezeit das Vorbild lieferten, welchem man die Begriindung der iibrigen 
Wissenszweige, wenn auch nicht immer mit dem gleichen Erfolge, nach- 
zubilden suchte. Es schien lange ganz unmoglich dieser Begriindung 
iiberhaupt noch etwas hinzu zu fiigen oder daran etwas zu andern. 

Um so auffallender und unerwarteter ist es, dass gegenwartig haupt- 
sachlich in Deutschland ziemlich lebhafte Controversen gerade iiber die 
Grundprincipien der analytischen Mechanik entstanden sind. Es ist 
dies gewiss nicht so zu verstehen, als ob die Ehrfurcht und Bewunde- 
rung, die wir dem Genius eines Newton, Lagrange oder Laplace zoUen, 
dadurch irgend wie geschmalert werden soUte. Diese haben aus den 
kleinen Anfangen, welche sie vorfanden, eine fiir alle Zeiten mustergiil- 
tige Herrin geschaffen. Sie hatten so viel des thatsachlich Neuen heraus 
zu arbeiten, dass sie sich nur aufgehalten und dem einheitlichen Ein- 
druck geschadet hatten, wenn sie bei gewissen Schwierigkeiten und 
Dunkelheiten zu lange verweilt hatten. Aber seitdem ist unsere Kennt- 

261 



262 Ludwig Boltzmann : 

nis von Thatsachen bedeutend gewachsen, unser Verstand ist geschult, 
so dass viele Vorstellungen, welche zu Zeiten Newtons noch den Gelehr- 
ten Schwierigkeiten machten, nun zum Gemeingut aller geworden sind. 
Dadurch erhielt man Musse die Construktion des Newton'schen Gebaudes 
gewissermassen mit der Lupe zu betrachten, und siehe es ergaben sich 
manche Schwierigkeiten, wie sie sieli ja dem Menschengeiste immer 
gerade da am meisten entgegen stellen, wo er die einfachsten Grund- 
lagen der Erkenntnis zu analysiren strebt. 

Diese Schwierigkeiten sind freilich mehr philosophischer oder wie man 
heutzutage sagt, erkenntnistheoretischer Natur. Wir Deutsche sind 
schon oft und viel verlacht worden wegen unserer Neigung zur philoso- 
phischen Speculation und in friiherer Zeit sicher oft mit Recht. Eine von 
den Thatsachen abgekehrte PhilosopMe hat nie etwas Brauchbares hervor- 
gebracht und kann es nicht hervorbringen. Von unmittelbar greifbarem 
Nutzen ist es vor allem, unsere Kenntnis der Thatsachen durch Experi- 
mente zu erweitern und auch unsere wissenschaftliche Naturkenntnis wird 
zunachst und am ausgiebigsten in dieser Weise gefordert. Aber trotz 
alledem scheint die Neigung die einfachsten Begriffe zu analysiren und 
sich iiber die Grundoperationen unseres Denkens Rechenschaft zu geben 
im Menschengeiste unbezwinglich. 

Viel hat sich auch die Methode dieser Analyse im Verlaufe der Zeit ver- 
vollkommnet, so dass dieselbe heutzutage wenn auch noch keineswegs sof ort 
praktisch fruchtbringend, doch lange nicht mehr so wesenlos ist, wie die 
alte Philosophie. Im Verlaufe der Geschichte erfahrt ja das ganze Cultur- 
bild der Menschheit stete und bedeutende Schwankungen. Die Deutschen 
sind nicht mehr die unpraktischen Traumer von ehemals. Sie haben es 
auf alien Gebieten der Experimentalwissenschaft, der Technik, Industrie, 
und Politik bewiesen. Die Bestrebungen der Amerikaner waren natur- 
gemass anfangs behufs Unterjochung des Grundes und Bodens der rein 
praktischen Thatigkeit der Industrie und Technik zugewandt. Aber 
sie sind es langst nicht mehr ausschliesslich und schon weist Amerika auf 
alien Gebieten der abstrakten Wissenschaft Forscher auf, die den hervor- 
ragensten Europas vollkommen ebenbiirtig zur Seite stehen. Da sie daher, 
meine Herren, einen Deutschen zu Vortragen in ihrem Lande geladen 
haben, so will ich es wagen ein Gebiet der Erkenntnistheorie mit ihnen 
zu betreten. 

Ich will zunachst wieder zuriick kommen auf die Bedenken, welche 
gegen die Fundamente der Newton'schen Mechanik erhoben worden sind 



Erste Vorlesung. 263 

oder (besser gesagt) zu den Stellen, wo diese noch einer naheren Beleuclit- 
ung, einer Analyse der Schlussweise und Sichtung der Begriffe zu bediir- 
fen scheinen. Bei Aufstellung der Bewegungsgesetze betrachtet Newton 
die Bewegung der Korper als eine absolute im Raume. Der absolute 
Raum ist aber nirgends unserer Erfahrung zuganglich. Erfahrungsmas- 
sig gegeben sind immer nur die relativen Lagenanderungen der Korper. 
Es wird also da gleich zu Anfang voUstandig liber die Erfahrung hin- 
ausgegaugen, was gewiss bedenklich ist in einer Wissenschaft, welche 
sicli nur die Aufgabe stellt Erfabrungsthatsachen darzustellen. Diese 
Schwierigkeit ist natiirlicb dem Genius Newtons keineswegs entgangen. 
AUein dieser glaubte ohne den Begriff eines absoluten Raumes zu keiner 
einfachen Formulirung des Traglieitsgesetzes gelangen zu konnen, um 
die es ihm an erster S telle zu thun war und ich glaube, dass er liierin auch 
Recht behalten hat ; denn so viel diese Schwierigkeit auch beleuchtet oder 
durchdacht wurde, so ist doch kaum ein wesentlicher Fortschritt erzielt 
worden. Neumann fiihrt statt des Newton'schen absoluten Raumes einen 
rathselhaften idealen Bezugskorper ein, womit er offenbar ganz ebenso 
wie Newton iiber die Erfahrung hinausgeht. Streintz stellt sich die 
Aufgabe derartige Begriffe oder Korper zu vermeiden, indem er lehrt 
wie man mittelst der Bewegung eines Gyroskops, auf welches keine oder 
bekannte Krafte wirken relativ gegen ein gewahltes Coordinatensystem 
entscheiden kann, ob fiir dieses Coordinatensystem die Newton'schen Be- 
wegungsgesetze gelten, ob es ein brauchbares Bezugssystem ist. Allein 
diese Streintz'schen Betrachtungen scheinen fiir die Fundamentirung der 
Mechanik wenig brauchbar, da sie ja bereits die Bewegungsgesetze ein- 
es rotirenden Kreisels und die Beurtheilung, ob auf denselben Krafte 
wirken oder nicht, voraussetzen, wozu schon die Kenntnis der Newton'- 
schen Bewegungsgesetze erforderlich ist. Lange versucht allerdings 
die Formulirung des Tragheitsgesetzes ohne irgend ein Bezugssystem 
bloss durch Betrachtung der relativen Bewegung. Sie gelingt ihm auch, 
fallt aber so complicirt und weitschweifig aus, dass man sich nur schwer 
entschliessen wird ein so wenig libersichtliches Gesetz an Stelle der ein- 
fachen Newton'schen Formel zu setzen. Selbstverstandlich geht auch 
der Vorschlag Mach's Gerade, welche durch die Gesammtheit aller Mas- 
sen der Welt bestimmt sind oder der Vorschlag den Lichtather an Stelle 
des absoluten Raums zu setzen, beide freilich in ganz anderer Weise iiber 
die Erfahrung hinaus. Ersterer Vorschlag kniipft namlich wieder an 
rein ideale transcendente Begriffe an, wogegen letzterer eine Aussage 



264 Ludwig Boltzmann: 

macht, welche zwar erfahrungsmassig moglicherweise bewiesen werden 
konnte, aber es gewiss noch nicht ist. Es miisste denn fiir den Ather 
eine ganz andere Mechanik gelten, dieser miisste etwa selbst die Ursache 
des Tragheitsgesetzes nicbt aber demselben unterworfen sein. Eine 
gleiche Schwierigkeit begegnet man bei Einfiihrung des Begriffs der 
Zeit. Auch diese wird von Newton als eine absolute eingefiihrt, wahrend 
uns eine solche niemals gegeben ist, sondern immer bloss die Gleichzei- 
tigkeit des Veiiaufs mehrerer Vorgange. Jedocb ist hier die Abhilfe 
leichter, indem man von einem Vorgange ausgeht, der sicb immer peri- 
odisch unter ganz gleichen Umstanden wiederholt. Freilich ist es nicht 
moglicb absolute Gleichheit der Umstande berzustellen, doch kann man 
im hochsten Grade wahrscheinlich machen, dass alle Umstande, die iiber- 
haupt wesentlichen Einfluss haben, die gleichen sind. Man kann dies 
noch dadurch erharten, dass man verschiedenartige Vorgange von dieser 
Eigenschaft (die Erddrehung, die Schwingungen eines Pendels, einer 
Chronometerfeder) untereinander vergleicht. Die Ubereinstimmung aller 
dieser Vorgange in der Anzeige gleicher Zeiten schliesst dann jeden 
Zweifel an der Brauchbarkeit der Methode aus. 

Eine dritte Schwierigkeit betrifft die Begriffe der Masse und Kraft. 
Dass die Newton'sche Definition der Masse als Quantitat der Materie 
eine nichts sagende ist, wurde langst erkannt. Aber auch beziiglich des 
Verhaltnisses der Kraft znr Masse ergeben sich Zweifel. Ist die Masse 
das allein Existirende und die Kraft nur eine Eigenschaft derselben oder 
ist umgekehrt die Kraft das wahrhaft Existirende oder ist ein Dualismns 
zweier getrennter Existenzen (Masse und Kraft) anzunehmen, so dass die 
Kraft eine von der Materie getrennt existirende Ursache der Bewegung 
der ersteren ist. Hinzu kam in neuerer Zeit noch die Frage, ob auch 
der Energie Existenz zuzuschreiben ist oder ob gar letztere das allein 
Existirende ist. 

Es war vor alien Kirclihoff, welcher in diesem Punkte schon der Art 
der Fragestellung entgegentrat. Oft ist ein Problem schon halb gelost, 
wenn die richtige Methode der Fragestellung gefunden ist. Kirchhoff 
wies es nun zuriick, dass es Aufgabe der Naturwissenschaft sei, das wahre 
Wesen der Erscheinungen zu entrathseln und ihre ersten metaphysischen 
Grundursachen anzugeben. Er reducirte die Aufgabe der Naturwissen- 
schaft vielmehr darauf, die Erscheinungen zu beschreiben. Kirchhoff 
nannte dies noch eine Beschrankung der Aufgabe der Naturwissenschaft. 
Wenn man aber so recht in die Art und Weise, ich mochte sagen in den 



Erste Vorlesung. 265 

Mechanismus unseres Denkens eindringt, so mochte man fast auch das 
leugnen. 

Alle unsere Vorstellungen und Begriffe sind ja nur innere Gedanken- 
bilder, wenn ausgesprochen Lautcombinationen. Die Aufgabe unseres 
Denkens ist es nun, dieselben so zu gebrauchen und zu verbinden, dass 
wir mit ihrer Hilfe allezeit mit grosster Leichtigkeit die richtigen Hand- 
lungen treffen und auch andere zu richtigen Handlungen anleiten. Die 
Metaphysik hat sich da dem niichternsten praktischsten Standpunkte 
angeschlossen, die Extreme beriihren sich. Die begrifflichen Zeichen, 
welche wir bilden, haben also nur eine Existenz in uns, die aussern 
Erscheinungen konnen wir nicht mit dem Masse unserer Vorstellungen 
messen. Wir konnen also formell derartige Fragen aufwerfen, ob bloss 
die Materie existirt und die Kraft eine Eigenschaft derselben ist oder 
ob letztere von der Materie unabhiingig existirt oder ob umgekehrt die 
Materie ein Erzeugnis der Kraft ist ; aber es haben alle diese Fragen gar 
keine Bedeutung, da alle diese Begriffe nur Gedankenbilder sind, welche 
den Zweck haben die Erscheinungen richtig darzustellen. Besonders 
klar hat dies Hertz in seinem beruhmten Buche liber die Principien der 
Mechanik ausgesprochen, nur stellt Hertz daselbst als erste Forderung 
die auf, dass die Bilder, welche wir uns construiren, den Denkgesetzen 
entsprechen mlissen. Gegen diese Forderung mochte ich gewisse Beden- 
ken erheben oder wenigstens sie etwas naher erliiutern. Gewiss miissen 
wir einen reichen Schatz von Denkgesetzen mitbringen. Ohne sie ware 
die Erfahrung voUkommen nutzlos; wir konnten sie gar nicht durch 
innere Bilder fixiren. Diese Denkgesetze sind uns fast ausnahmslos ange- 
boren, aber sie erleiden doch durch Erziehung, Belehrung, und eigene 
Erfahrung Modifikationen. Sie sind nicht voUkommen gleich beim 
Kinde, beim einfachen ungebildeten Manne, oder beim Gelehrten. Wir 
werden dies auch einsehen, wenn wir die Denkrichtung eines naiven Volkes 
wie der Griechen mit der der Scholastiker des Mittelalters, und diese wieder 
mit der heutigen vergleichen. Gewiss gibt es Denkgesetze, welche sich 
so ausnahmslos bewahrt haben, dass wir ihnen unbedingt vertrauen, sie 
fiir aprioristisehe unabanderliche Denkprincipien halten. Aber ich 
glaube doch, dass sie sich erst langsam entwickelten. Ihre erste Quelle 
waren primitive Erfahrungen der Menschheit im Urzustand, allmalig 
erstarkten sie und verdeutlichten sich durch complicirtirte Erfahrungen 
bis sie endlich ihre jetzige scharfe Formulirung annahmen ; aber als unbe- 
dingt oberste Richter mochte ich die Denkgesetze nicht anerkennen. 



266 Ludwig Boltzmann: 

Wir konnen nicht wissen ob sie nicht doch nocli die eine oder andere 
Modification erfahren werden. Man erinnere sich doch mit welcher 
Sicherheit Kinder oder Ungebildete iiberzeugt sind, dass man durch das 
blosse Gefiihl die Richtung nach oben von der nach unten an alien Orten 
des Weltraums miisse unterscheiden konnen und wie sie daraus die 
Unmoglicbkeit der Antipoden deduciren zu konnen glauben. Wiirden 
seiche Leute Logik schreiben, so wiirden sie das sicber fiir ein a priori 
evidentes Denkgesetz halten. Ebenso wurden anfangs gegen die Coper- 
nicanische Theorie vielfach aprioristische Bedenken erhoben und die Ge- 
schichte der Wissenschaft weist zablreiche Fiille auf, wo man Satze bald 
begriindete, bald widerlegte mittels Beweisgriinden, die man damals fiir 
evidente Denkgesetze hielt, wahrend wir jetzt von ihrer Nicbtigkeit iiber- 
zeugt sind. Ich mocbte daher die Hertz'sche Forderung dabin modificiren, 
dass in so weit wir Denkgesetze besitzen, welcbe wir durch stete Bewahr- 
heitung in der Erfahrung als zweifellos richtig erkannt haben, wir die 
Richtigkeit unserer Bilder zunachst an diesen erproben konnen, dass 
aber die letzte und alleinige Entscheidung iiber die Zweckmassigkeit der 
Bilder in dem Umstande liegt, dass sie die Erfahrung moglichst einfach 
und durchaus treffend darstellen und dass gerade hierin wieder die Probe 
fiir die Richtigkeit der Denkgesetze liegt. Haben wir die Aufgabe des 
Denkens iiberhaupt und der Wissenschaft insbesondere in dieser Weise 
erfasst, so ergeben sich uns Consequenzen welche im ersten Augenblick 
etwas Frappirendes an sich haben. Eine Vorstellung von der Natur wer- 
den wir falsch nennen, wenn sie uns gewisse Thatsachen unrichtich dar- 
stellt oder wenn es offenbar einfachere gibt, welche die Thatsachen klarer 
darstellen, besonders wenn sie allgemein bewahrten Denkgesetzen wider- 
spricht, doch sind immerhin Theorien moglich, welche eine grosse Zahl von 
Thatsachen richtig darstellen in andern Punkten aber unrichtig sind, denen 
also eine gewisse relative Wahrheit zukommt. Ja es ist sogar moglich, dass 
wir in verschiedener Weise ein System von Bildern der Erscheinungen 
construiren konnen. Jedes dieser Systeme ist nicht gleich einfach, stellt 
die Erscheinungen nicht gleich gut dar. Aber es kann zweifelhaft, 
gewissermassen Geschmacksache sein, welches wir fiir das Einfachere 
halten, durch welche Darstellung der Erscheinungen wir uns mehr befrie- 
digt fiihlen. Die Wissenschaft verliert hiedurch ihr einheitliches Geprage. 
Man hielt doch ehedem daran fest, dass es nur Eine Wahrheit geben 
konne, dass die Irrthiimer mannigfaltig seien, die Wahrheit aber nur eine 
einzige ist. Dieser Ansicht muss von unserem jetzigen Standpunkte ent- 



Erste Vorlesimg. 267 

gegen getreten werden, freilich ist der Unterschied der neuen Ansicht 
gegeniiber der alten ein mehr formeller. Es war nie zweifelhaft, dass der 
Mensch niemals den vollen Inbegriff aller Wahrheit zu erkennen vermoge. 
Diese Erkenntniss ist nur ein Ideal. Ein ahnliches Ideal besitzen wir aber 
auch gemass unserer jetzigen Vorstellung. Es ist das voUkommenste Bild, 
das alle Erscheinungen in der einfachsten und zweckmassigsten Weise 
darstellt. Wir wenden daher nach der einen Anschauungsweise den 
Blick melir auf das unerreichbare Ideal, welches nur ein einheitliches ist, 
nach der andern auf die Mannigfaltigkeit des Erreichbaren. 

Wenn wir nun die Uberzeugung haben, dass die Wissenschaft bloss 
ein inneres Bild, eine gedankliche Construction ist, welche sich mit 
der Mannigfaltigkeit der Erscheinungen niemals decken, sondern nur 
gewisse Tlieile derselben libersichtlich darstellen kann, wie werden wir 
zu einem solchen Bilde gelangen? wie es moglichst systematisch und 
iibersichtlich darstellen konnen ? Es war frliher eine Methode beliebt, 
welche der von Euclid in der Geometric angewandten nachgebildet ist 
und daher die Euclidische heissen soil. Dieselbe geht von moglichst 
wenigen, moglichst evidenten Satzen aus. In den altesten Zeiten wurden 
diese als a priori evident, als direkt dem Geiste gegeben betrachtet, wess- 
halb man sie als Axiome bezeichnet. Spater dagegen schrieb man ihnen 
lediglich den Charakter von hinliinglich verblirgten Erfahrungssatzen 
zu. Aus diesen Axiomen wurden dann bloss mit Hilfe der Denkgesetze 
gewisse Bilder als nothwendig deducirt und man glaubte so einen Beweis 
gefunden zu haben, dass diese die einzig moglichen seien und nicht durch 
andere ersetzt werden konnten. Als Beispiel flihre ich die Schliisse an, 
welche zur Ableitung des Krafteparallelogramms oder des Ampere'schen 
Gesetzes oder des Beweises dienten, dass die zwischen zwei materiellen 
Punkten wirkende Kraft in die Richtung ihrer Entfernung fallen und 
eine Function dieser Entfernung sein miisse. 

Aber die Beweiskraft dieser Schlussweise geriet allmalig in Miscredit, 
der erste Schritt hiezu war der, dass man wie schon frliher geschildert 
von einer a priori evidenten Grundlage zu einer bloss erfahrungsmassig 
bewahrten iiberging. Man sah ferner ein, dass auch die Deduktionen aus 
jener Grundlage nicht ohne zahlreiche neue Hypothesen gemacht werden 
konnten, und so wies endlich Hertz darauf hin, dass namentlich im Gebiete 
der Physik unsere Uberzeugung von der Richtigkeit einer allgemeinen 
Theorie im Wesen noch nicht auf der Ableitung derselben nach der 
Euclidischen Methode, sondern vielmehr darauf beruhe, dass diese Theo- 



268 Ludwig Boltzmann: 

rie in alien bislier bebannten Fallen uns zu richtigen Schliissen in Beziig 
auf die Erscheinungen leite. Er machte von dieser Ansicht zuerst in 
seiner Darstellung der Maxwell'schen Grundgleichungen der Lehre von der 
Elektricitat und dem Magnetismus Gebrauch, indem er vorschlug sich um 
deren Ableitung aus gewissen Grundprincipien gar nicht zu bekiimmern, 
sondern sie einfach an die Spitze zu stellen und die Recbtfertigung bie- 
von darin zu suchen, dass man nachweisen konne dass sie binterher iiber- 
all mit der Erfabrung iibereinstimme ; denn diese bleibt docb scbliesslicb 
die einzige Ricbterin iiber die Braucbbarkeit einer Tbeorie, deren Urtheil 
inapellabel und unerscbiitterlicb ist. In der Tbat wenn wir auf die Gegen- 
stande naber eingeben, welche mit dem Gegenstande am meisten zusam- 
menbangen, das Tragbeitsgesetz, das Krafteparallelogramm und die iibri- 
gen Fundamentalsatze der Mecbanik, so werden wir die verscbiedenen 
Beweise, welcbe in alien Lebrbiicbern der Mecbanik fiir jeden einzelnen 
dieser Satze geliefert werden, bei weitem nicbt so iiberzeugend fiuden, als 
die Tbatsacbe, dass sicb alle aus dem Inbegriffe aller dieser Satze gezo- 
genen Consequenzen so ausgezeicbnet in der Erfabrung bestatigt baben. 
Die Wege, auf denen wir zu den Bildern gelangten, sind nicbt selten die 
verscbiedensten und von den mannigfaltigsten Zufallen abhangig. 

Mancbe Bilder wurden im Verlauf von Jabrbunderten durcb das Zu- 
sammenwirken vieler Forscber erst allmalig construirt, wie die der mecba- 
niscben Warmetbeorie. Mancbe wurden von einem einzigen, genialen For- 
scber, aber oft wieder auf sebr verscblungenen Umwegen, gefunden und 
erst dann von andern in die verscbiedenartigste Beleucbtung geriickt, 
wie die besprocbene Maxwell'scbe Tbeorie der Elektricitat und des 
Magnetismus. Es wird nun eine Darstellungsweise geben, welcbe ganz 
besondere Vorziige aber audi wieder ibre Mangel besitzt. Diese Dar- 
stellungsweise bestebt darin, dass wir eingedenk unserer Aufgabe, bloss 
innere Vorstellungsbilder zu construiren, anfangs lediglicb mit gedank- 
licben Abstractionen operiren. Hiebei nebmen wir nocb gar keine Riicksiebt 
auf etwaige Erf abrungstbatsacben. Wir bemliben uns lediglicb mit mog- 
licbster Klarbeit unsere Gedankenbilder zu entwickeln, und aus denselben 
alle moglicben Consequenzen zu zieben. Erst binterber, nacbdem die 
ganze Exposition des Bildes voUendet ist, priifen wir dessen Ubereinstim- 
mung mit den Erfabrungstbatsacben, motiviren also in dieser Weise erst 
binterber, warum das Bild gerade so und nicbt anders gewahlt werden 
musste, worilber wir vorber nicbt die leiseste Andeutung geben. Wir 
woUen dies als die deduktive Darstelluns: bezeicbnen. Die Vorziige dieser 



Erste Vorlesung. 269 

Darstellung liegen auf der Hand. Sie lasst zunachst gar keinen Zweifel 
darixber aufkommen, dass sie nicht die Dinge an sich selbst bieten will, 
sondern bloss ein inneres geistiges Bild und dass ihr Bestreben bloss 
darin besteht dieses geistige Bild zu einer geschickten Bezeichnung der 
Ersclieinungen zu formen. Da die deduktive Methode nicht fortwahr- 
end aussere uns aufgezwungene Erfahrungen mit inneren von uns will- 
kiirlich gewahlten Bildern vermengt, so ist es ihr weitaus am leichtesten 
diese letzteren klar und widerspruchsfrei zu entwickeln. Es ist namlich 
eines der wichtigsten Erfordernisse dieser Bilder, dass sie voUkommen 
klar sind, dass wir niemals in Verlegenheit sind, wie wir sie in jedem 
bestimmten Falle formen soUen und dass wir jedes Mai das Resultat ein- 
deutig und unzweifelhaft aus denselben ableiten konnen. Gerade diese 
Klarheit leidet durch zu frtihe Vermischung mit der Erfahrung und wird 
bei der deduktiven Darstellungsweise am sichersten gewahret. Dagegen 
tritt bei dieser Darstellungsweise besonders die Willkiirlichkeit der Bil- 
der scharf hervor, indem man mit ganz willkiirlichen Gedankenconstruc- 
tionen beginnt und deren Notwendigkeit nicht anfangs motivirt sondern 
erst hinterher rechtfertigt. Davon, dass nicht auch andere Bilder erdacht 
werden konnten, die ebenso mit der Erfahrung stimmen wiirden, wird 
kein Schatten eines Beweises geliefert. Es scheint dies ein Fehler zu 
sein, ist aber vielleicht gerade ein Vorzug, wenigstens fiir denjenigen, 
der die friiher auseinandergesetzte Ansicht von dem Wesen jeder Theo- 
rie hat. Ein wirklicher Fehler der deduktiven Methode besteht dagegen 
darin, dass der Weg nicht sichtbar wird, auf welchem man zur Auffindung 
des betreffenden Bildes gelangte. Aber es ist ja im Gebiete der Wissen- 
schaftslehre die Regel, dass der Zusammenhang der Schliisse dann am 
deutlichsten hervortritt, wenn man diese moglichst in ihrer natiir- 
lichen Reihenfolge und ohne Riicksicht auf den oft krummen Weg 
auseinandersetzt, auf welchem dieselben gefunden wurden. Hertz 
hat auch im Gebiete der Mechanik in seinem bereits citirten Buche 
ein Muster einer solchen rein deduktiven Darstellung gegeben. Ich 
glaube den Inhalt des Hertz'schen Buches bier als bekannt voraussetzen 
zu konnen und mich daher auf eine ganz kurze Charakteristik des- 
selben beschranken zu diirfen. Hertz geht von materiellen Punkten 
aus, welche er als reine Gedankenbilder betrachtet. Auch die Masse 
definirt er ganz unabhangig von aller Erfahrung durch eine Zahl, die 
wir uns jedem materiellen Punkte beigelegt denken miissen, namlich die 
Anzahl der einfachen Massenpunkte, welche er enthalt. Aus diesen 



270 Ludwig Boltzmann: 

abstrakten Begriffen construirt er eine ZTinachst natiirlicli bloss wie die 
Punkte selbst in Gedaaken vorhandene Bewegimg. Der Begriff der 
Kraft felilt dabei voUstandig. An ibre Stelle treten gewisse Beding- 
imgen, welcbe sich in der Form von Gleicbungen zwiscben den Differen- 
zialen der Coordinaten der materiellen Punkte scbreiben. Diese letzteren 
sind nun mit gegebenen Anfangsgescbwindigkeiten ausgestattet und 
bewegen sicli in jeder folgenden Zeit nacb einem sebr einfacben Gesetze, 
welcbes sobald die Bedingungsgleicbungen gegeben sind, die Bewegung 
fiir alle Zeiten eindeutig bestimmt. Hertz spricbt es dabin aus, dass die 
Summe der mit den Massen multiplicirten Quadrate der Abweicbungen 
der materiellen Punkte von der geradlinigen, gleicbformigen Bewegung 
fiir jeden Zeitmoment ein Minimum sein muss oder nocb kiirzer, dass 
die Bewegung in den geradesten Babnen gescbiebt. Es bat dieses Gesetz 
die grosste Abnlicblicit mit dem Gauss'scben Principe des kleinsten 
Zwanges, ja es ist gewissermassen derjenige spezielle Fall, der eintritt, 
wenn man das Gauss'scbe Princip auf ein System von Punkten anwen- 
det, welcbe zwar einem Zwange, aber keinerlei sonstigen aussern Kraften 
unterworfen sind. 

Icb babe in meinem Bucbe welcbes den Titel bat " Vorlesungen iiber 
die Principe der Mecbanik" ebenfalls eine rein deduktive Darstellung der 
Grundprincipe derselben versucbt, aber in ganz anderer Weise, weit mebr 
an die gewonlicbe Bebandlung der Mecbanik ankniipfend. Icb gebe wie 
Hertz von reinen Gedankendiugen, exakten materiellen Punkten aus ; icb 
beziebe deren Lage auf ein ebenfalls gedacbtes recbtwinkliges Coordina- 
tensystem und denke mir ein geistiges Bild von der Bewegung derselben 
zunacbst in folgender Weise construirt. Jedesmal, wenn sicb zwei der- 
selben in irgend einer Entfernung r befinden, soil jeder derselben eine 
Bescbleunigung in der Ricbtung von r erfabren, welcbe eine Function 
/(r) dieser Entfernung ist, iiber die spater nacb Belieben verfiigt wer- 
den kann. Es sollen ferner die Bescbleunigungen beider Punkte in 
einem zu alien Zeiten unveranderlicben Zablenverbaltnisse steben, 
welcbes das Massenverbiiltnis der beiden materiellen Punkte definirt. 
Wie wir uns die Bewegung aller materiellen Punkte zu denken baben, 
das ist dann eindeutig durcb die Angabe bestimmt, dass die wirklicbe 
Bescbleunigung jedes Punktes die Vectorsumme aller fiir ibn nacb der 
friiheren Regel gefundenen Bescbleunigungen ist und sicb zur scbon vor- 
bandenen Gescbwindigkeit des Punktes ebenfalls so addirt wie Vector- 
grossen addirt werden. Wober diese Besclileunigungen kommen und 



Erste Vorlesung. 271 

warum ich gerade die Vorschrift gebe sich das Bild in dieser Weise zu 
construiren wird nicht weiter disoutirt. Es geniigt dass das Bild ein voU- 
kommen klares ist, welches in geniigend vielen Fallen durch Rechnungen 
im Detail ausgearbeitet werden kann. Dasselbe findet seine Rechtfertig- 
ung erst darin, dass sich die Function /(r) in alien Fallen so bestimmen 
lasst, dass die gedachte Bewegung der eingebildeten materiellen Punkte 
in ein naturgetreues Abbild der wirklichen Erscheinungen iibergeht. 

Wir haben durch diese Behandlungsweise, welche wir die rein deduc- 
tiye genannt haben, die Frage nach dem Wesen der Materie, der Masse, 
der Kraft, freilich nicht gelost, aber wir haben diese Fragen umgangen, 
indem wir ihre Voranstellung vollstandig iiberfliissig gemacht haben. 
In unserem Gedankenschema sind diese Begriffe ganz bestimmte Zahlen 
und Anweisungen zu geometrischen Constructionen, Ton denen wir wis- 
sen, wie wir sie denken und ausfiihren soUen, damit wir ein brauchbares 
Bild der Erscheinungswelt erhalten. Was die eigentliche Ursache sei, 
dass die Erscheinungswelt sich gerade so abspielt, was gewissermassen 
hinter der Erscheinungswelt verborgen ist und sie treibt, das zu erfor- 
schen, betrachten wir nicht als Aufgabe der Naturwissenschaft. Ob es 
Aufgabe einer andern Wissenschaft sei und sein konne, oder ob wir da 
nicht vielleicht bloss nach Analogic mit anderen verniinftigen Wortzu- 
sammenstellungen hier Worte aneinandergefiigt haben, welche in diesen 
Verbindungen keinen klaren Gedanken ausdriicken, das kann hier voll- 
standig dahingestellt bleiben. Wir haben durch diese deductive Methode 
ebenso wenig die Frage nach dem absoluten Raume und der absoluten 
Bewegung gelost ; allein auch diese Frage hat keine padagogischen 
Schwierigkeiten mehr ; wir brauchen sie nicht mehr beim Beginne der 
Entwickelung der mechanischen Gesetze vorzubringen, sondern konnen 
sie erst besprechen, wenn wir alle mechanischen Gesetze abgeleitet haben. 
Denn da wir ja anfangs ohnehin nur gedankliche Constructionen vor- 
fiihren, so nimmt sich ein gedachtes Coordinatensystem keineswegs fremd- 
artig unter denselben aus. Es ist eben eine der verschiedenen uns 
verstandlichen und gelaufigen Constructionsmittel aus denen wir unser 
Gedankenbild zusammensetzen, nicht mehr und nicht weniger abstract, 
als die materiellen Punkte, deren Bewegung relativ gegen das Coordina- 
tensystem wir uns vorstellen und fiir welche aUein wir zunachst die 
Gesetze aussprechen und mathematisch formuliren. Beim Vergleiche 
mit der Erfahrung finden wir dann, dass ein unveranderlich mit dem 
Fixsternhimmel verbundenes Coordinatensystem praktisch voUkommen 



272 Ludwig Boltzmawn: 

ausreicht um die Ubereinstimmung mit der Erfahrung zu sichern. Was 
fiir ein Coordinatensystem wir einstens werden zu Grunde legen miissen, 
wenn wir einmal die Bewegung der Fixsterne durch mechanisclie For- 
meln ausdriicken konnten, diese Frage steht auf unserm Repertoire an 
allerletzter Stelle und wir konnen jetzt alle die Hypothesen von Streintz, 
Mach, Lange etc. welche eingangs erwahnt warden mit Leichtigkeit 
discutiren, da uns alle Gesetze der Mechanik bereits zur Verfiigung stehen. 
Wir komraen nicht in dieselbe Verlegenheit wie friiher, wo wir diese 
complicirten Betracbtungen der Entwickelung des Tragbeitsgesetzes 
batten voranstellen miissen. Freilicb baben wir dafiir bei der deduc- 
tiven Metliode wieder einen Beweis zu liefern, der bei den alten Methoden 
iiberflilssig war. Da wir bei den letzteren direct von den Erscbeinungen 
ausgingen, so verstand es sicb von selbst, dass die Gesetze der Erscbein- 
ungen nicbt von der Wabl des lediglicb binzugedacbten Coordinaten- 
systems abbangen konnen, und es musste eben frappiren, dass sicb diese 
Gesetze anders und viel complicirter ausnebmen, wenn wir ein sicb dreben- 
des Coordinatensystem einfiibren. Bei der deductiven Metbode aber 
baben wir von vorne berein dem Coordinatensystem im Bilde die gleicbe 
RoUe angewiesen wie den materiellen Punkten. Es ist ein integrirender 
Bestandtbeil des Bildes und es kann uns nicbt Wunder nebmen, dass 
dieses verscbieden ausfallt, wenn wir das Coordinatensystem anders 
wahlen. Wir miissen bier im Gegentbeil aus dem Bilde selbst den 
Beweis liefern, dass dieses sicb nicbt andert, wenn wir beliebige andere 
Coordinatensysteme einfiibren, so lange sicb diese nicbt relativ gegen 
einander dreben oder nicbt mit Bescbleunigung relativ gegen einander 
bewegen. 

Wir woUen nun die zuletzt besprochene Darstellungsweise meines 
Bucbes mit der Hertz'scben vergleicben. Herr Classen bat meine Dar- 
stellung als eine Polemik gegen Hertz aufgefasst und die Sacbe so darge- 
stellt, als ob icb mir einbildete etwas unbedingt Besseres als Hertz 
vorgebracbt zu baben. Nicbts weniger als dies. Icb erkenne die 
Vorziige des Hertz'scben Bildes unbedingt an, aber nacb dem Principe, 
dass es moglicb und wiinscbenswert ist, fiir ein und dieselbe Erscbeinungs- 
gruppe mebrere Bilder aufzustellen, glaube icb, dass mein Bild neben dem 
Hertz'scben nocb seine Bedeutung bat, indem es gewisse Vorziige auf- 
weist, welcbe dem Hertz'scben feblen. Die Principe der Mecbanik, 
welcbe Hertz aufstellt, sind von aussererordentlicber Einfacbheit und 
Scbonbeit. Sie sind natiii-licb nicbt voUstandig frei von Willkiirlicb- 



Erste Vorleswig. 273 

keit, aber ich mochte sagen die Willkiirlichkeit ist auf ein Minimum 
beschrankt. Das von Hertz unabhangig von der Erfahruug construirte 
Bild hat eine gewisse innere VoUendung und Evidenz. Es enthalt an 
sich nur wenig willkiirliche Elemente. Hingegen steht offenbar main 
Bild weit zuriick. Letzteres enthalt weit mehr Ziige, welche den Stempel 
davon an sich tragen, dass sie nicht durch eine innere Notwendigkeit 
bestimmt sind, sondern bloss eingefiigt wurden, um hinterher dann eben 
die Ubereinstimmung mit den Erfahrung zu ermoglichen. Es enthalt 
auch eine ganz willkiirliche Function und von den vielen Bildern, 
welche entstehen, wenn dieser Function alle moglichen Formen er- 
theilt werden, entsprechen nur ganz wenige wirklichen Vorgangen, 
wahrend man beim Hertz'schen Bilde sofort sieht, dass wenn iiberhaupt 
einige, so doch jedenfalls nur wenige andere Bilder moglich sein 
konnen, welche sich einer gleichen Einfachheit und inneren VoUendung 
erfreuen, so weckt mein Bild sofort die Idee, dass es wohl noch so 
manche andere geben mag, welche die Erscheinungen mit gleicher Voll- 
kommenheit darstellen. Trotzdem giebt es aber wieder Punkte, in 
denen mein Bild dem Hertz'schen iiberlegen ist. Hertz kann zwar einige 
Erscheinungen in directer Weise, aus seinem Bilde erklaren, oder wie 
wir lieber sagen wollen, mittelst desselben darstellen, so die Bewegung 
eines materiellen Punktes auf einer vorgeschriebenen Flache oder Kurve 
oder die Drehung eines starren Korpers um einen fixen Punkt, beides 
wolgemerkt, so lange keine fremdartigen aussern Krafte V^orhanden sind. 
Man stosst aber sofort auf Schwierigkeiten, sobald man die gewohnlich- 
sten in der tagiichen Erfahrung vorkommenden Vorgange darstellen will, 
bei denen Krafte wirken. Betrachten wir zunachst eine der allgemeinsten 
und wichtigsten Naturkrafte, die Gravitation. Als Fernkraft diirfen wir 
dieselbe vom Hertz'schen Standpunkte natiirlich nicht auffassen. Es sind 
nun zwar zahlreiche Versuche gemacht worden, sie durch Wirkung eines 
Mediums mechanich zu erklaren. AUein es ist bekannt, dass keiner der- 
selben zu einem recht bestimmten, entscheidenden Resultate gefiihrt hat. 
Einer der bekanntesten ist die schon von Lesage aufgestellte, spater von 
Lord Kelvin, Isenkrahe und andern wieder aufgenommene Theorie der 
Molekularstosse. Dieselbe ist abgesehen davon, dass ihre exacte Durch- 
fiihrbarkeit, noch immer zweifelhaft, ist fiir die Hertz'sche Theorie 
unbrauchbar, well schon die Erklarung eines einzigen elastischen Stosses 
aus derselben Schwierigkeiten bereitet, wie wir sogleich sehen werden. 
Man miisste also erst eine ganz neue Theorie schaffen, die Gravitations- 



274 Ludwig Boltzmann: 

wirkung etwa durcli Wirbel, Pulsationen oder Ahnliches erklaren, 
wobei die Theilchen des betreffenden Mediums ebenfalls nicht durch 
Krafte im alten Sinne, sondern bloss durch Bedingungsgleicliungen von 
der Form, wie sie Hertz aufstellt verkniipft sein dlirften. Selbst, wenii 
dies gelingen sollte, so hiesse dies doch zu einem ganz willklirlichen Bilde 
greifen, welches hochst wahrscheinlich im Verlaufe der Zeit durch ein 
ganz anderes ersetzt werden miisste. Der Vorwurf, welchen Hertz gegen 
die alte Mechanik erhebt, dass sie ein viel zu weites Bild gibt, indem von 
alien moglichen die Kraft darstellenden Functionen /(>•) nur ganz wenige 
eine praktische Verwendung haben lasst sich in verstarktem Masse gegen 
sein eigenes Bild kehren, sobald man dasselbe auf bestimmte Falle anwen- 
den will. Schon bei der Anwendung auf die Gravitation muss man aus 
alien moglichen Medien, welche Fernwirkung vermitteln konnten irgend 
ein bestimmtes auswahlen, worin wohl noch mehr Unbestimmtheit und 
WiUkiirlichkeit liegt als in der Wahl gewisser Functionen /(r). 

Die elektrischen und magnetischen Krafte hat bekanntlich Maxwell 
in seinen ersten Arbeiten mit Erfolg durch die Wirkung eines Mediums 
erklart. AUein abgesehen davon, dass dieses Medium einen hochst 
complicirten Ban hatte und von Eigenschaften strotzte, die den Stempel 
der WiUkiirlichkeit nnd eines rein provisorischen Charakters an sich 
trugen, so ware es fiir Hertz wieder nicht einmal brauchbar, indem seine 
Theile ebenfalls von Kraften im alten Sinne der Mechanik zusammen- 
gehalten werden. Ja auch die Eigenschaften der elastischen, tropf- 
barfliissigen und gasformigen Korper miissten durch neue Bilder ersetzt 
werden, da die bisherigen alle auf die Annahme von zwischen den Theil- 
chen wirkenden Kraften gegriindet sind. Man hat also nur folgende 
Walil, entweder man lasst die Natur des Mechanismus, welcher die 
Gravitation, die elektrischen und magnetischen Erscheinungen erzeugen 
soil, unbestimmt und willklirlich. Dadurch entsteht eine unertragliche 
Unanschaulichkeit, indem man genothigt ist immer mit Gleichungen zu 
operiren, von denen man nur einige ganz allgemeine Eigenschaften kennt, 
deren spezielle Form aber voUstandig nnbekannt ist, oder man bemiiht 
sich einen bestimmten Mechanismus zu wahlen, wodurch man dann wieder 
iu eben so viele Willkiirlichkeiten als Schwierigkeiten verwickelt wird. 

Doch ich will noch an einem viel einfacheren Beispiele die Schwierig- 
keiten zeigen, auf welche die Anwendung des Hertz'schen Fundamental- 
gesetzes schon in den trivialsteu Fallen stosst. 

Es seien drei Massen m^, u und m^ mit der Bedingung gegebeu, dass 



Mrste Vorlesung. 275 

sowohl die Entfernung m^ u als audi die u m^ stets gleich derselben 
Grosse a sein soil. Lassen wir dann die Masse u immer kleiner vverden, 
so erhalten wir einen voUkommen dem Geiste der Hertz'schen Meclianik 
entsprechenden Fall, der uns eiii getreues Bild des folgenden Natur- 
vorgangs gibt. In einer elastischen Hohlkugel von der Masse m^ bewege 
sich eine kleine elastische VoUkugel ; die Differenz der Radien sei 2 a. 
Wir liaben also hier ein Beispiel eines und desselben Naturvorganges, 
welcber auf zwei ganz verschiedenen Wegen erklart werden kann, eines- 
tbeils aus der Molekulartheorie, anderstheils nacli der Ton Hertz 
angegebenen Methode. Aber so verhalten sich nicht alls Vorgange. 
Sclion der ganz triviale Fall des Stosses zweier elastiscben Vollkugeln 
ist aus dem Hertz'schen Schema nur durch zeimlich willkiirlich gewahlte 
Mechanismen oder complicirte Annahmen iiber ein Zwischenmedium 
ableitbar, da ja die Hertz'sche Methode Ungleichungen ausschliesst. Es 
fiihrt also die Hertz'sche Methode schon in den einfachsten Fallen zu 
den grossten Complicationen. 

Ich betone hier nochmals, dass diese Ausfilhrungen keineswegs den 
Zweck haben soUen, den hohen Wert des Hertz'schen Bildes zu leugnen, 
"welcher in der logischen Einfachheit seiner Grundprincipien besteht. 
Es ware ja moglich, dass man in ferner Zukunft einmal alle Wirkungen 
durch Medien erkliiren kann, deren Eigenschaften nicht phantastisch 
gewahlt, sondern durch die Natur der Sache in nahe liegender und un- 
zweideutiger Weise geboten werden. Es ware moglich, dass die Theil- 
chen dieser Medien nicht Krafte im alten mechanischen Sinne aufeinander 
ausiiben, sondern dass man mit Bedingungsgleichungen im Hertz'schen 
Sinne zwischen den Coordinaten der Elementartheilchen ausreichen 
wiirde. Von diesem Augenblicke an hatte die Hertz'sche Mechanik 
in unzweifelhafter Weise den Sieg davongetragen und alle andern Dar- 
stellungen hatten nur mehr historisches Interesse. Ob man das einstige 
Eintreffen eines solchen Zeitmomentes fiir wahrscheinlich halt oder nicht 
ist naturlich eine reine Geschmackssache. Bewiesen ist nicht einmal die 
Moglichkeit einer derartigen Entwicklung unserer Erkentnis. Wir wer- 
den daher auf unserem gegenwartigem Standpunkte zu jenem Ideale mit 
Bewunderung aufblicken, auch das Unserige zur Beforderuijg der An- 
naherung an dasselbe beitragen. Aber einstweilen werden wir solche 
einfache und unmittelbar brauchbare Bilder, welche sich jetzt schon 
ins Detail durchfiiliren lassen neben den Hertz'schen nicht entbehren 
konnen. 



276 Imdwig Boltzmann: 

ZWEITB VORLESUNG. 

Ich habe in der vorigen Vorlesung zwei Bilder der mechamsclien Er- 
scheinungen besprochen, welche beide rein deductiv sind, das Hertz'sche 
und das in meinem Buche iiber Mechanik dargestellte. Das letztere un- 
terscheidet sich dem Wesen nach nicht von den alteren Theorien der 
Mechanik. Ich bemiihte mich nur diese durch eine moglichst conse- 
quente Darstellung gegen etwaige Einwiirfe besonders gegen die Be- 
denken zu sichern, welche Hertz in der Vorrede seines Buches gegen 
die altere Mechanik erhebt. Gerade zu diesem Zwecke schien sich die 
rein deductive Darstellung am besten zu eignen, weil sie das Bild ganz 
unabhangig von den Thatsachen in moglichster Klarheit zu entwickeln 
erlaubt. Man konnte jedoch das Bild auch nach der entgegengesetzten 
Methode entwickeln, indem man unmittelbar von den Thatsachen aus- 
ginge, wie sie sich der unbefangenen Beobachtung bieten, aus diesen That- 
sachen die Bilder erst allmalig entstehen liesse und jede Abstraction erst 
dann einfiihrte, wenn sie auf keine Weise mehr abgewiesen werden kann. 
Diese letztere Darstellung woUen wir die inductive nennen. Dieselbe 
hat der deductiven gegeniiber den Nachtheil, dass die Bilder von Anfang 
an nicht so rein hervortreten, daher ihre innere Consequenz nicht so klar 
zu libersehen ist. AUein sie hat auch wieder den Vortheil, dass' sie an 
Stelle der lange Zeit hindurch rein abstracten von der Wirkliehkeit 
abgekehrten Darstellungsweise der deduktiven Methode rein an das 
unmittelbar Gegebene und Gelaufige ankniipfende setzt und moglichst 
klar erkennen lasst, wie die abstracten Bilder entstanden sind und 
warum wir gerade zu diesen Bildern unsere Zuflucht nehmen. Um die 
Vorziige und Nachtheile der deductiven Methode mit der inductiven zu 
vergleichen, ware es nicht ganz zweckmassig die im vorigen Vortrage 
geschilderte Methode mit den alteren in der Mechanik iiblichen Darstel- 
lungsweisen zu vergleichen, da die letzteren beide Methoden vermischen 
und dadurch wie mir scheint die Klarheit beeintrachtigen. So werden in 
der Regel sehr bald abstracte Begriffe, wie der des materiellen Punktes, 
der Masse etc., eingefilhrt, diese aber nicht, wie von uns in der vorigen Vor- 
lesung als.rein gedankliche Werkzeuge aufgefasst. Es werden vielmehr 
davon mehr oder minder unbestimmte und nichts sagende Definitionen 
gegeben. So wird der materielle Punkt als ein Korper definirt, welcher 
so klein ist, dass seine Ausdehnung vernachlassigt werden kann. Man 
meint damit etwa, dass seine Tragheitsmomente beziiglich einer durch 



Zweite Vorlesung. 277 

seinen Schwerpunkt gehenden Axe gegeniiber denen beziiglich einer 
andern Axe verschwinden, die sich davon in einer Entfernung befindet, 
die von der Grossenordnung der Entfernungen ist, welche bei unsern 
Experimenten fiir gewohnlicb vorkommen oder Ahnliches. Da aber der 
Begriff des Triigheitsmomentes, Schwerpunkts etc. noch nicht entwickelt 
worden ist, so wiisste ich nicht was man sich unter einem Korper, an dem 
eine der wichtigsten Eigenschaften, namlich die Ausdehnung vernach- 
lassigt werden kann, denken soil. Die Masse wird oft definirt durch 
die Wirkung einer und derselben Kraft auf verschiedene Korper, aber 
wie soil man constatiren, dass die Kraft dieselbe ist, wenn sie einmal 
auf diesen einmal auf jenen Korper wirkt? Es wird daher das Beste 
sein, wenn wir versuchen noch eine neue rein inductive Darstellung der 
Grundprincipien der Mechanik wenigstens mit einigen Strichen zu ski- 
ziren. Wir bleiben dabei unserm Princip treu, dass wir vorlaufig keines- 
wegs eine einzige beste Darstellung der Wissenschaft erstreben, sondern 
dass wir es fiir niitzlich halten moglichst viele verschiedene Darstel- 
lungen zu versuchen, von denen jede ihre besondern Vorziige, freilich 
auch wieder jede ihre Mangel hat. Das Hauptaugenmerk wird dabei 
wieder darauf zu richten sein alle Inconsequenzen und logischen Fehler 
zu vermeiden, keinen Begriff oder keine Annahme stillschweigend einzu- 
schmuggeln, sondern uns aller gemachten Hypothesen mit moglichster 
Klarheit bewusst zu werden. Es versteht sich von selbst, dass ich hier 
bei der Kiirze der mir zur Verfiigung stehenden Zeit nicht die ganze 
Mechanik erschopfend darstellen kann. Ich werde nur versuchen einige 
Andeutungen zu geben. Es ware wol auch kaum moglich eine so schwie- 
rige Aufgabe auf einmal ganz der Losung zuzufiihren. Viel wird an 
dem ersten Versuche noch mangelhaft sein und erst allmalig werden sich 
die Begriffe sichten und die Darstellungsweisen vervollkommnen. "Wir 
werden da gerade denjenigen Weg einschlagen miissen, der dem in der 
vorigen Vorlesung geschilderten und in meinem Buche liber Mechanik 
verfolgten, direct entgegengesetzt ist. Die abstracten Begriffe des mate- 
riellen Punktes, der Masse, Kraft etc., von denen wir dort ausgingen, 
werden wir nun zwar auch nicht ganz vermeiden konnen ; denn sie sind 
einmal die Grundpfeiler, auf welche die Mechanik aufgebaut ist. Aber 
wir werden sie jetzt so spat als moglich einfiihren und wahrend wir sie 
friiher postulirten, werden wir jetzt moglichst an die Erfahrung ankniip- 
fen und unsere Resultate daraus zu deduciren suchen. Daher sind jetzt 
auch diejenigen Gesetze, welche friiher die einfachsten schienen, nicht 



278 Ludwig BoUzmann: 

voranzustellen, wie z. B. das Tragheitsgesetz. Dieses wird gewohnlich 
dahin ausgesprochen, dass ein materieller Punkt, welcher jedem ausseren 
Einflusse entzogen ist, sich geradlinig und gleichformig bewegt. Abge- 
sehen von der Schwierigkeit, die im Begriffe des materiellen Punktes 
liegt, konnen wir nun aber keinen Korper so weit von alien iibrigen 
entfernen, dass er jedem Einflusse entzogen ist und ware dies mogiich, 
so konnten wir seine Bewegung nicht mehr beobachten, gescbweige denn 
deren Geradlinigkeit und Gleichformigkeit constatiren. Wenn man aber 
das Tragheitsgesetz an Korpern verificiren will, an denen sich alle darauf 
wirkenden Krafte das Gleicbgewicht halten, so mlisste man die gesammte 
Lehre vom Gleichgewicbte schon vorausscbicken. Man pflegt also in 
der gewohnliehen Darstellung Abstractionen und Thatsacben vielfach 
zu vermiseben, was zu vermeiden eben im folgenden unsere Hauptauf- 
gabe sein soil, da wir uns vornebmen streng von reinen Erfabrungsthat- 
sacben auszugehen. 

Die erste Unbequemlicbkeit, die uns hiebei entgegentritt ist folgende: 
Friilier batten wir es bei Aufstellung der ersten Grundprincipien mit rein 
Gedachtem zu tbun, das wir in unserer Idee formen konnen, wie wir 
wollen, und wovon wir verlangen konnen, dass es immer exact unseren 
Anforderungen entspricbt, jetzt dagegen wollen wir von den direct 
beobacbteten Erscbeinungen ausgehen, welcbe immer sebr zusammenge- 
setzt und complicirt sind. Wollen wir daraus Grundgesetze gewinnen, 
so miissen wir die Erscbeinungen immer generalisiren und idealisiren, so 
dass wir scbon nicbt mehr ganz exacte Thatsacben vor uns haben son- 
dern Vorgange, welcbe in der Natur immer nur mit grosserer oder gerin- 
gerer Annaherung realisirt sind. Wir konnen es daher auch nicht ganz 
vermeiden Vorstellungen und Thatsacben zu vermengen aber wir suchen 
dies wenigstens auf das kleinste Mass zuriick zu f iihren und bestreben uns 
es nicht versteckt zu thun, sondem wo wir dazu gezwungen sind uns 
dessen klar bewusst zu bleiben. 

Die Erscbeinungen, welcbe uns gegeben sind, haben eine ausserordent- 
lich verschiedene Natur. Die eiufachsten bestehen in Ortsveriinderungen 
eines Korpers, welcher dabei weder seine Gestalt noch seine sonstigen 
Eigenschaften irgendwie zu verandern scheint. Schon diese einfacbe 
Erscheinung ist in gewisser Beziehung eine idealisirte. In den wenigsten 
Fallen andert der Korper seine Gestalt absolut gar nicht ; ja alle, selbst 
die unveranderlichsten Korper konnen durch sebr starke Krafte zer- 
brechen, durch Hitze, chemische Wirkungen, zu voUiger Veranderung ibrer 



Zweite Vorlesung. 279 

Eigenschaften reranlasst werden. Aber es gibt sehr viele Korper, die doch 
ihre Gestalt wahrend der mannigfaltigsten Bewegungen durch lange Zeit 
nicht bemerkbar andern. Wir nennen sie feste Korper und bilden uns 
das Ideal eines absolut unveranderlichen Korpers, welclien wir einen 
starren nennen. Andere Korper, die Fllissigkeiten andern wahrend ihrer 
Bewegung ihre Gestalt in der mannigfaltigsten Weise, entweder bei 
(natiirlich wieder nur angenahert) gleich bleibendem Volumen, (die tropf- 
baren Fliissigkeiten) oder unter steter sehr merkbarer Anderung des Vol- 
umens, (die Gase). Man kann die letzteren Erscheinungen auf die erstern 
zuriickfiihren, indem man annimmt, dass die Fliissigkeiten aus sehr vielen 
sehr kleinen TheUchen bestehen, deren Bewegung unabhangig von ein- 
ander, die Gestaltanderung hervorruft. Andert sich dabei die durch- 
schnittliche Entfernung je zweier Nachbartheilchen, so ist dieselbe auch 
mit Volumanderung verkntipft. Es ist nun die Frage, soU man sich die 
Anzahl dieser Theilchen mathematisch unendlich oder bloss sehr gross 
aber endlich denken. Viele Erfahrungsthatsachen deuten darauf bin, 
dass die letztere Annahme gemacht werden muss, welche auch philoso- 
phisch die befriedigendere ist. Aber da eine unzweifelhafte experi- 
mentelle Entscheidung bisher nicht erfolgt ist, so woUen wir getreu den 
Principien, nach denen wir jetzt vorzugehn beabsichtigen, diese Frage 
voUstandig in suspense lassen. 

AUe Ortsveranderung heissen Bewegungen. Die Lehre von den 
Bewegungserscheinungen ist die Mechanik, welche sich in die Geo-, Hydro- 
und Aero-mechanik abtheilt, je nachdem man es mit der Bewegung 
fester, tropfbarer oder gasformiger Korper zu thun hat. Die Mechanik 
umfasst ihrer Definition gemass auch die Bedingungen, unter denen sich 
ein Korper garnicht bewegt. 

Es gibt noch vielerlei Erscheinungen der Schall, die Warme, das 
Licht, die elektrischen und magnetischen Erscheinungen, die ganzliche 
Anderung der Eigenschaften von Korpern bei chemisehen Prozessen, die 
Geruchs-, Geschmackerscheinungen etc. Letztere sind wahrscheinlich 
nur spezielle Falle von Verdampfungs- oder chemisehen Erscheinungen, 
und daher fiir die Physik von geringerer Wichtigkeit, welche ja die 
Action auf die Nerven und die Fortleitung durch dieselben bis zum 
Bewusstwerden der Physiologie und Psychologic iiberlasst. Aber sie 
miissen hier doch ebenfalls erwahnt werden. 

Es ist unzweifelhaft nachgewiesen, dass den Schallerseheinungen 
Bewegungen der Korper zu Grunde liegen. Naturgemass suchte man 



280 Ludwig Boltzmann: 

auch Licht, Elektricitat und Magnetismus, so wie die chemischen 
Erscheinungen durch Bewegungserscheinungen gewisser hypothetischer 
Medien oder Iiypothetischer kleinster Theile zu erklaren und bis vor 
Kurzem war wohl jeder Physiker ilberzeugt, dass hiemit dem Wesen nach 
die eigentliche Aufgabe der Physik ausgesprochen sei. Erst vor wenigen 
Decennien wurde unwiderleglich nachgewiesen, dass die besonders in 
Deutschland friiher allgemein verbreitete Theorie der elektrischen und 
magnetischen Fluide mit den Thatsachen nicht in Ubereinstimmung 
gebracht werden kann. Man wurde nun vorsich tiger, man suchte zwar 
die elektrischen und magnetischen Erscheinungen zunachst wieder durch 
mechanische Wirkung eines Mediums zu erklaren, allein da man hiebei 
nicht zu einem bestimmten eindeutigen Erfolge gelangte, so neigen in 
neuester Zeit manche Physiker zur Ansicht, dass es wol ein iibereilter 
Schluss sei, dass sich alle Erscheinungen durch Bewegungsphanomene 
mlissten erklaren lassen oder in unsere Ausdrucksweise iibertragen, dass 
es vielleicht gar nicht moglich sei durch die Bilder von Ortsverander- 
ungen von Punkten und Korpertheilen allein sich ein ausreichendes 
Bild der Erscheinungen zu verschaffen ; dass man dazu noch qualitativ 
verschiedene Bilder wie dielektrische und magnetische Polarisationen, 
chemische Zustande oder anderes dazunehmen miisse. Es wiirde 
dadurch die Einheit der Naturwissenschaft ausserordentlich leiden, da 
man auf keinen Fall die alten einfachen Bilder vermeiden konnte und 
uns noch eine Menge fremdartiger dazu einfllhren miisste. Es wiirde 
dann auch die Bedeutung der Mechanik als Grundlage der gesammten 
Naturwissenschaft, auf welcher alle iibrigen Theorien derselben beruhen, 
in Frage gestellt. Aber immer hatte noch die Mechanik als die Lehre 
der einfachsten Erscheinungen, ohne die irgend welche andere nicht 
denkbar sind, alien andern physikalischen Theorien voranzugehn. Wenn 
man daher auch einerseits nicht leugnen kann, dass der Beweis der 
mechanischen Erklarbarkeit aller Naturerscheinungen noch nicht geliefert 
ist, so ist doch sicher ebenso wenig ein Beweis geliefert, dass gewisse 
Naturerscheinungen nicht durch mechanische Bilder erklarbar sein 
konnten, und man kann hochstens die Ansicht aussprechen, dass bei gewis- 
sen Naturerscheinungen der Versuch einer mechanischen Erklarung heute 
noch zu frlih kommt. Die allgemeine Frage an sich kann erst nach 
Jahrhunderten entschieden oder wenigstens in ein wesentlich neues Licht 
gerlickt und geklart werden. Wir wollen uns daher mit der Discussion 
des "Fiir" oder "Wider" hier nicht aufhalten, sondern kehren zur Beweg- 



Zweite Vorlesung. 281 

ung eines festen Korpers K zuriick, den wir sogleich idealisiren, indem 
wir ihn als absolut starr denken. Wir fassen denselben nicht etwa als 
einen materiellen Punkt, sondern als einen erfahrungsmassig gegebenen, 
wenigstens dem Scheine nacli continuirlicli ausgedehnten Korper auf. 
Wir miissen freilich wieder sogleich mit einer Abstraction einsetzen ; wir 
konnen die Bewegung des Korpers nicht auf einmal als Ganzes erfassen, 
da er ja (wenigstens fiir uns scheinbar) aus unendlich vielen Theilen 
besteht. Wir konnen bloss die Bewegung einzelner Punkte desselben 
klar mit dem Auge und Gedanken verfolgen. Wir wollen daher sehr 
kleine Stellen desselben A, B, C, . . . mit feinen selbstverstandlich 
ebenfalls starr mit dem Korper verbundenen Marken bezeichnen etwa 
mit feinen Farbepunkten, Mehlstaubchen oder durch die Kreuzung zweier 
feiner Linien etc. Wenn wir eine ausserordentlich enge Hohlung in den 
Korper bohren, so konnen wir audi Punkte im Innern desselben wirklich 
bezeichnen und wir konnen es audi oline die Hohlung in Gedanken, 
wenn wir uns etwa einen geometriscli ahnlichen liohlen oder durchsichti- 
gen oder sonst an dieser Stelle zuganglichen Korper vorstellen. Es ist 
freilich schon wieder eine Idealisirung, wenn wir uns diese bezeiclineten 
Stellen als mathematische Punkte denken ; allein wir bleiben doch dem 
thatsachlich Realen viel naher, wenn wir die Bewegung des ausgedehnten 
Korpers durch solche Punkte beschreiben und an erster Stelle einfache 
Gesetze fiir die Medianik ausgedehnter Korper zu gewinnen suchen, als 
wenn wir direkt mit den Gesetzen fiir die Bewegung einzelner materieller 
Punkte beginnen. Wir konnen jetzt genauer beschreiben, was es heisst, 
wenn wir sagen die Gestalt eines Korpers andert sich wahrend seiner 
Bewegung nicht. Wir konnen durch Anlegen eines Massstabes oder 
zweier Zirkelspitzen, die wir dann auf einen Massstab iibertragen die Ent- 
fernung je zweier beliebiger Punkte des Korpers Kd. h. zweier beliebiger 
hervorgehobener Marken auf demselben messen. Wenn dieselbe fiir alle 
Punktepaare zu alien Zeiteii unverandert bleibt, so sagen wir die Gestalt 
des Korpers ist unveranderlich. Fiir die Unveranderlichkeit des Mass- 
stabes oder Zirkels liaben wir freilich keine objective Garantie, sondern 
nur die empirische, dass uns dieselben an alien Korpern, welche schon dem 
Augenscheine nach ihre Gestalt nicht andern, die richtige Anzeige liefern. 
Wenn alle festen Korper in gleicher Weise ihre Dimensionen mit der 
Zeit andern wiirden, so konnten wir dies natiirlich nicht bemerken. 
Wir haben auch durchaus nicht die Absicht zu erklaren, wieso es feste 
Korper gibt, wieso wir die Entfernungen der damit fest verbundnen 



282 Ludwig Boltzmann: 

Marken messen konnen. Wir nehmen dies als Erfahrungsthatsachen bin, 
nur die Gesetze der Veranderung der Entfernungen der Marken ver- 
schiedener Korper oder auch desselben Korpers falls dieser niclit starr ist, 
woUen wir durch unsere Vorstellungsbilder darstellen. 

Vorbedingung jeder wissenscbaftlicben Erkenntniss ist das Princip der 
eindeutigen Bestimmtheit der Naturvorgange, auf die Mecbanik ange- 
wandt der eindeutigen Bestimmtheit aller Bewegungen. Dasselbe sagt 
aus, dass die Bewegungen der Korper nicbt rein zufallig bald so, bald 
anders vor sicb gebn, sondern dass sie durch die Umstande, unter denen 
sich der Korper befindet, eindeutig bestimmt sind. Wenn jeder Korper 
sich wie er woUte bewegte, wenn unter gleichen Umstanden bald diese, 
bald jene Bewegung je nach Zufall erfolgte, so konnten wir dem Verlaufe 
der Erscheinungen nur neugierig zusehen nicht ihn erforschen. Auch 
hierin liegt wieder eine Unbestimmtheit, die Umstande, unter denen die 
Bewegung irgend eines Korpers vor sich geht, umfassen streng genom- 
men das ganze Universuni. Dasselbe ist nie zweimal im selben Zustande. 
Wir miissen also unsere Bedingungen daliin reduziren, dass immer die- 
selbe Bewegung erfolgt, wenn die unmittelbare Umgebung sich in dem- 
selben Zustande befindet. Wir sind bier bei der inductiven Methods 
wieder in einer weit ungiinstigeren Lage als bei der Deductiven. Denn 
da wir bei der letztern mit der Aufzahlung der Wirkungsgesetze ohne 
Riicksicht auf jede Erfahrung beginnen, so liegt es ganz in unserer 
Hand gleich anfangs wUlkiirlich festzustellen, von welchen Umstanden 
die Bewegung eines Korpers abhangt und welche darauf ohne Einfluss 
sind. Bei der inductiven Metbode hingegen miissen wir den Begriff der 
unmittelbaren Umgebung eines Korpers, deren Zustand auf seine Beweg- 
ung von Einfluss ist, nach der Erfahrung bestimmen. Nach der Nahe- 
wirkungstheorie sind es nur die unmittelbar anliegenden Volumelemente, 
welche die Bewegung irgend eines Volumelementes bestimmen. Nach 
dieser Theorie wirkt die Erde nicht direct anziehend auf den schweren 
Korper sondern sie wirkt nur auf die Volumelemente eines Mediums, 
durch welche sich die Wirkung bis zum schweren Korper fortpflanzt. 
Aber wenn wir den Principien unserer jetzigen Darstellungsweise treu 
bleiben wollen, so diirfen wir nicht die Nahewirkungstheorie zur Basis des 
gesammten Gebaudes der Mecbanik machen, wir diirfen vielmehr hiezu 
nur Gesetze verwenden, welche nichts Willkiirliches enthalten, sondern uns 
durch die Erfahrung eindeutig und notwendig aufgedrangt werden. Die 
Nahewirkungstheorie aber, so wahrscheinlich sie vielleicht manchem 



Zweite Vorlesung. 283 

a priori erscheint, geht docli vollstandig iiber das rein Thatsachliche hiiiaus 
und kann heutzutage noch keineswegs ins Detail ausgearbeitet werden. 
Wir wiirden da in denselben Fehler verfallen, den wir der Hertz'schen 
Darstellungsweise vorgeworfen haben. Wir miissten entweder ganz will- 
klirliche spezielle Hypothesen fiir die Art und Weise der Naliewirkung 
erfinden oder uns mit allgemeinen unbestimmten Vorstellungen iiber die- 
selbe begnligen. 

Wir miissen daher die ganze Erde zur Umgebung des schweren Kor- 
pers rechnen aber Mond und Sterne dabei ausser Acht lassen, da letztere 
keinen bemerkbaren Einfluss ausiiben. Es ist also wieder eine reine 
Annahme, welche wir erst nachtraglich durch die Erfahrung rechtfertigen 
miissen, dass wir die unmittelbare Umgebung immer so abzugrenzen ver- 
mogen, dass wir aUes Wesentliche einschliessen und dass wir so factisch 
zu einer AufsteUung von Bewegungsgesetzen gelangen konnen. 

Wie werden wir uns nun bei unserer jetziger Darstellungsweise dem 
absoluten Raume und der absoluten Zeit gegenliber verhalteu? An 
einem Theile des absoluten Eaumes konnen wir keine Zirkelspitze ein- 
setzen sondern nur an materiellen Korpern. Wir konnen daher nur 
die Bewegung von materiellen Korpern relativ gegen einander bestimmen. 
Wir diirfen jetzt nicbt wie bei der deduct! ven Metkode das Gedanken- 
bild eines fingirten Coordinatensystems unter die von uns gegenwartig 
allein betrachteten realen Korper mengen. Dem Geiste unserer Methode 
entsprechend miissen wir vielmehr unsere Betrachtungen moglichst dem 
historischen Entwickelungsgange der Mechanik anschliessen. Galilei 
hat die einfacben Bewegungsgesetze gefunden, indem er die Bewegung 
relativ gegen die Erde studirte. Seinem Beispiele folgend werden wir 
daber ausser dem Korper K, dessen Bewegung wir beschreiben woUen, 
noch ein System von anderen Korpern in die Betrachtungen mit einbe- 
ziehen, welche die Bedingung erflillen, dass alle ihre Punkte ihre Ent- 
fernungen von einander nicht andern, dass sie also alle relativ ruhen. 
Dieses System nennen wir das Bezugssystem. Wenn wir daher die 
Bewegung eines festen Korpers gegen ein Bezugssystem studiren und 
wenn A, B, C . . . markirte Punkte des ersteren, U, F, Gr . . . solche des 
letztern sind, so andern sich weder die Entfernungen AB, AQ . . . noch 
EF, EG- . . . und unsere Aufgabe besteht bloss darin, die Gesetze 
der Veranderungen, der Entfernungen AE, AF, BF . . . aufzustellen. 
Natiirlich sind hiebei auch wieder vielerlei Idealisirungen notwendig. 
Wir werden kein System von Korpern als Bezugssystem auffinden 



284 Ludwig Boltzmann: 

konnen, welche so beschaffen sind, dass sie zu alien Zeiten relativ gegen- 
einander ihre Lage absolut beibehalten. Es genligt, wenn diese Beding- 
ung angenahert durch geniigend lange Zeit erfiillt ist. 

Ferner konnen wir nicht wissen, ob wir dieselben Gesetze erhalten, 
wenn wir das eine oder andere Bezugssystem wahlen. Wir werden 
daher jedenfalls ein solches Bezugssystem zu wahlen haben, dass wir ein- 
fache Gesetze fiir die Bewegung erhalten. Es zeigt sich in der That, 
dass die Gesetze, welche wir bei zu Grundelegung des Fixsternhimmels 
als Bezugssystem erhalten nicht ohne kleine Correctionen auf die Beweg- 
ung relativ gegen die Erde angewandt werden konnen und es muss als 
ein fiir die Entwickelung der Mechanik ausserordentlich giinstiger Zufall 
bezeichnet werden, dass der Einfluss der Erddrehung auf die verschiedenen 
Bewegungen, welche wir auf ihrer Oberflache beobachten ein so ausser- 
ordentlich geringer ist. Sonst ware es weit schwieriger gewesen die 
Grundgesetze der Mechanik herzuleiten. Diesem Umstande ist es zu ver- 
danken, dass wir fiir die Bewegungen auf der Erde den Erdkorper als 
Bezugssystem wahlen konnen. Wir erhalten hiedurch einfache Gesetze, 
denen die wirklichen Bewegungen freilich nicht mit absoluter Genauig- 
keit folgen, aber die Abweichungen sind so gering, dass sie sich fast der 
Beobachtung entziehen. Dies konnten wir freilich nicht a priori wissen ; 
aber es ist kein logischer Fehler, wenn wir zunachst die Gesetze der 
Relativbewegung gegen die Erde studiren. Finden wir einfache Gesetze, 
so ist es wieder kein logischer Fehler, deren Anwendung auf die Beweg- 
ung der Planeten relativ gegen das Fixsternsystem zu versuchen. Bei 
dieser Erweiterung zeigt sich dann erst einestheils, dass sie auch fiir den 
ersten Fall angenahert richtig sein miissen, anderseits aber, dass derselbe 
doch kleiner Correctionen bedarf. Diese Correctionen sind so klein 
dass sie uns bei Auffindung der Gesetze aus den irdischen Bewegungen 
nicht storten, dass sie aber jetzt nachdem wir ihre Grossenordnung kennen 
gelernt haben doch mit feinen Hilfsmitteln beobachtet werden konnen. 
Dass die wirklichen Bewegungen dann gerade die durch diese Correctionen 
bedingten Eigenthtimlichkeiten zeigen, rechtfertigt nachher in glanzender 
Weise unsere Methode. Hiemit ist wieder die padagogische Schwierig- 
keit beseitigt, welche durch die Relativitat aller Bewegungen bedingt 
Avird. Die Frage, auf welches Bezugssystem wir die Fixsternbewegungen 
zu beziehen haben, ist hiemit freilich nicht gelost, aber es liegt in keiner 
Weise eine Notwendigkeit vor, diese Frage vor Aufstellung der sammt- 
lichen Gesetze der Mechanik zu behandeln. 



Zweite Vorlesung. 285 

Wir haben bisher liber die Gestalt und Anordnung der Korper des 
zu Grunde gelegten Bezugssystems keine besondere Annahme gemacht. 
Es hat nun keine Schwierigkeit mit denselben drei fixe auf einandei" 
rechtwinklige Gerade vorbunden zu denken, welche man als Coordinaten- 
axen wahlen kann. Die Lage jedes an dem betreffenden Korper mar- 
kirten Punktes ist dann zu jeder Zeit durch dessen rechtwinklige 
Coordinaten beziiglich dieses Coordinatensystems bestimmt. Wenn 
sich diese mit der Zeit nicht andern, so befindet sich der Korper 
in relativer Ruhe gegen das Bezugssystem. Wenn sie sich andern, 
so ist er in Bewegung Um den letztern Fall beschreiben zu konnen, 
ist noch die genaue Fixirung des Zeitmasses erforderlich. Gerade 
so wie wir schon mit Hilfe des Augenmasses oder des Tastgefiihles 
grossere raumliche Ausdehnungen von kleineren unterscheiden, einen 
genauen zahlenmassigen Ausdruck der Raumgrosse aber nur durch Ver- 
gleich mit einem rationell construirten Massstabe gewinnen konnen, so 
konnen wir auch schon durch das Gefiihl (den Zeitsinn) langere Zeit- 
raume von kiirzern unterscheiden, miissen uns aber ein genaues quantita- 
tives Zeitmass durch die Hilfsmittel verschaffen, welche schon in der 
ersten Vorlesung angedeutet wiirden. Wir miissen uns da vor allem 
eine Reihe von Vorgangen verschaffen, bei denen wir vollkommen oder 
besser gesagt, thunlichste Garantie haben, dass sie sich in gleichen Zeiten 
abspielen. Wir konnen etwa ganz gleiche Korper unter ganz gleichen 
Umstanden fallen lassen oder ganz gleiche Pendel um gleiche Strecken 
aus der Ruhelage entfernen., Wenn das erste die Ruhelage erreicht, 
lassen wir das zweite seine Bewegung beginnen etc. Ob wir gegenseitige 
Storungen wirklich gentigend vermieden haben, kann natiirlich nur der 
Vergleich mit verschiedenen analogen Versuchen zeigen. Wir sehn 
natiirlich bald, dass auch ein Pendel die verschiedenen sich folgenden 
Schwingungen nahe unter den gleichen Umstanden voUzieht und konnen 
diese zur Zeitmessung benutzen. Freilich ist der absolute Isochronismus 
der Schwingungen wieder ein Ideal, Temperatur, Barometerstand, Sonne 
und Mond haben darauf Einfluss, aber wie alle diese storenden Umstande 
bei gut gearbeiteten Chronometern moglichst vermieden werden, wie 
durch eine treibende Kraft die Schwingungen sehr lange erhalten werden, 
dass man, wenn ein bestimmtes Chronometer endlich unbrauchbar wird, 
dafiir ein anderes moglichst gleichbeschaffenes substituiren kann, das 
alles ist nicht mehr Sache unserer gegenwartigen allgemeinen Betraeh- 
tungen. 



286 Ludwig BoUzmann : 

Wir wahlen einen bestimmten Zeitmoment z. B. den, der einem 
bestimmten willkiirlich gewahlten Durchgang durch die Ruhelage ent- 
spricht, als Zeitmoment Null, den des nachsten Durchgangs durch die 
Ruhelage als Zeit 1, die weiter folgenden als die Zeiten 2, 3 u.s.w. Die 
Unterabtheilungen konnen wir durch schneller schwingende Stimmgabeln 
oder durch Bewegungen bestimmen, die sich fiir grossere Intervalle unter 
alien Umstanden als geniigend gleichformig erwiesen und von denen wir 
Ursache haben dies auch fiir kleinere Intervalle zu vermuten. So gewin- 
nen wir die Zeiten J, \ u.s.w und es lasst sich keine Grenze der 
Unterabtheilung feststellen. Die negativen Zahlen bezeichnen die 
Schwingungen vor derjenigen der wir die Zeit Null zugeordnet haben. 
In dieser Weise konnen wir alle Zeiten durch positive, negative, ganze, 
gebrochene, irrationale Zahlen darstellen, wie wir die Langen durch die 
Zahl darstellen, welche angibt, wie oftmals sie die Langeneinheit enthal- 
ten. Die Differenz der Zahlen, welche zwei gegebene Zeiten darstellen 
heisst das dazwischen liegende Zeitintervall oder die Zeitdifferenz auch 
die inzwischen vorflossene Zeit. Unsere gewohnliche Zeiteinheit leiten 
wir von der Umdrehungszeit der Erde ab, deren Gleichformigkeit aber 
bei Ableitung der Principien der Mechanik wol besser durch einfachere 
Vorgange controlirt wird, da es ohne Kenntnis der mechanischen Gesetze 
nicht so ohne welters evident ist, dass die Umdrehungsgeschwindigkeit 
an alien Stellen der Erdbahn dieselbe bleibt. 

Wir kehren nun zuriick zu unserem Korper K, den wir auf ein mit 
dem gewahlten Bezugssysteme fest verbundenes Coordinatensysten Ox, 
Oy, Oz beziehen. Ein auf demselben hervorgehobener Punkt befinde 
sich zu einer bestimmten Zeit tm A und habe die rechtwinkeligen Coor- 
dinaten x, y, z. Wir verbinden ihn durch die Gerade OA mit dem Goor- 
dinatenursprunge : Diese Gerade heisst der Lagenvector des Punktes A, 
ihre Projectionen auf die drei Coordinatenaxen sind die drei Coordinaten 
X, y, z. Wenn nun der Korper eine gewisse gegebene Bewegung macht, 
so miissen wir zunachst jeden Zeitmoment der Bewegung etwa durch 
Vergleichung der gleichzeitigen Bewegung unseres Chronoskops durch 
eine Zahl darstellen. Es wird zu jeder Zeit eine bestimmte Lage des 
Korpers gehoren, daher auch des Punktes A desselben, daher auch be- 
stimmte Werte der Coordinaten y, x, z, welche wir uns ebenfalls durch 
reine Zahlen (ganze oder gebrochene Vielfache der Langeneinheit) dar- 
gestellt denken. Zu jedem Zahlenwerte der Zeit t gehort also ein ein- 
deutig bestimmter Zahlenwert der Coordinate x, x ist eine eindeutige 



Zweite Vorlesung. 287 

Function Yon t, ebenso y und z. Wir schreiben dies so x = ^(f), 
y = %(i), z = ylr(t') und nennen t das Argument oder die independente 
Variabele, x, y, z aber die dependenten Variabeln. Wir konnen es zu- 
nachst als hinlanglich sicher gestellte Erfahrungsthatsache betrachten, 
dass ein Korper nie aus einer Lage plotzlich verschwindet und im 
nachsten Zeitmomente in einer andern um Endliches davon Ver- 
schiedenen wieder zum Vorschein kommt und dass dies auch von jedem 
Theile eines Korpers gilt, dass also ^, %, -^Ir continuirliche Functionen 
der Zeit sind, d. h. ihre Zuwachse verschwinden um so mehr je Ideiner 
der entsprechende Zuwachs der Zeit ist. Die von den verschiedenen 
Lagen des Punktes A zu den verschiedenen Zeiten gebildete Curve nen- 
nen wir die Bahn dieses Punktes, denjenigen Theil derselben, welcher 
alien Lagen, die wahrend einer gegebenen Zeit durchlaufen werden ent- 
spricht den wahrend dieser Zeit zuriick gelegten Weg. 

Nicht ganz so sicher als die Continuitat der Functionen (f), ^i "^ ist 
es, ob sie auch differenzirbar sind. Man driickte sich in der alten 
Mechanik folgendermassen aus. Es lege ein Punkt eines Korpers, wahr- 
end einer sehr kleinen Zeit Bt einen sehr kleinen Weg Ss zuriick. Es sei 
nun a priori evident, dass sich wahrend dieser kleinen Zeit, die Umstande, 
unter denen sich der Korper befindet nur sehr wenig geandert haben kon- 
nen, dass es daher, wahrend der naclist folgenden Zeit St wieder einen 
sehr nahe gleichen und gleich gerichteten Weg Bs zuriicklegen muss, so 
dass also fiir kleine Zeiten sowohl der Weg als auch die Coordinatenzu- 
wachse der verstrichenen Zeit proportional sein miissen. Man glaubte 
damals iiberhaupt, dass jede iiberall endliche continuirliche Function einen 
Differenzialquotienten haben muss. Weierstrass hat bekanntlich gezeigt, 
dass dies ein Irrthum ist. Bezeichnen wir z. B. mit y die Weierstrass- 
ische Reihe so nahert sich der Zuwachs des y, der irgend einem Zuwachse 
des z entspricht an alien Stellen immer mehr der NuUe, wenn sich der 
betreffende Zuwachs das x der NuUe nahert und trotzdem nahert sich 
der Quotient beider Grosseu niemals einer bestimmbaren Grenze. Bei 
der deductiven Darstellung ergibt sich hieraus wieder nicht die mindeste 
Schwierigkeit. Wir konnen ja dann unser Bild formen, wie wir woUen 
und einfach die Differenzirbarkeit von vornherein in dasselbe aufneh- 
men, es damit rechtfertigend, dass das Bild hinterher mit der Erfahrung 
stimmt. Aber jetzt ist es unsere Absicht von der Erfahrung auszugehn. 
Nun lehrt uns zwar diese, dass sehr haufig, wahrend kleiner noch beob- 
achtbarer Zeiten der Weg eines Punktes eines Korpers um so genauer 



288 Ludwig Boltzmann: 

der verflossenen Zeit proportional ist, je kiirzer diese ist, woraus wir wolil 
auf die Differenzirbarkeit der Functionen (^, %, -^ scbliessen konnen. 
AUein wir kennen auch Beispiele sehr rascher Oscillationen und konnen 
nicht exact beweisen, ob nicht in gewissen Fallen Bewegungen vorbanden 
sind, wie z. B. die Warmebewegungen der Molekiile, welcbe durcb eine 
der Weierstrass'scben Function abnlicbe besser als durch eine Differen- 
zirbare dargestellt werden. Docb sind dies allerdings Dinge von gering- 
erer Wicbtigkeit und wir wollen daber die Differenzirbarkeit der Coor- 
dinaten nacb der Zeit unsern weitern Uberlegungen zu Grunde legen. 
Unter dieser Voraussetzung existiren die Ableitungen der Functionen 
<^, x^ ■^ nacb der Zeit. Wir nennen sie die Componenten der Geschwin- 
digkeit des Punktes A des Korpers. Die Gescbwindigkeit selbst konnen 
wir in folgender Weise construiren : Es befinde sicb der markirte Punkt 
des Korpers zur Zeit tin A zur Zeit ^ + S^ in B, so dass also OA, und OB 
die dazu gehorigen Lagenvectoren sind. Die Gerade AB ist dann das, 
was man die DiflFerenz der beiden Vectoren nennt. Wir construiren 
nun einen Vector, welcber die Ricbtung AB bat und dessen Lange der 
Quotient AB dividirt durcb ht ist. Ferner sucben wir die Grenze, wel- 
cber sicb dieser Vector in Grosse und Ricbtung nahert, wenn ht immer 
mebr abnimmt. Die so bestimmte Lange ist die Gescbwindigkeit, die 
Ricbtung aber, der sicb der Vector nabert, die Gescbwindigkeitsricbtung. 
Wir woUen bier nocb eine Bemerkung anfiigen. Damit wir den Weg 
durcb die verflossene Zeit dividiren konnen, miissen beide durcb reine 
Zablen ausgedriickt sein und wir baben geseben wie dies gescbiebt. 
Wablen wir die Langeneinbeit a mal so gross, so wird die Zabl, welcbe 
nun eine gewisse Lange ausdriickt a mal kleiner. Es ist moglicb, dass 
auch andere Grossen dieselbe Eigenscbaft baben, dass sie durcb a mal 
kleinere Zablen ausgedriickt erscbeinen, sobald wir die Langeneinbeit 
a mal vergrossern. Von alien so bescbaffenen Grossen sagen wir dann, 
dass sie die Dimension einer Lange baben. Jede Lange, (der Weg, die 
Coordinaten etc.) bat daber selbstverstandlicb die Dimension einer Lange. 
Die Zabl, welcbe uns die Zeit t ausdriickt, ist natlirlicb unabbangig von 
der gewablten Langeneinbeit, wird aber a mal kleiner, wenn wir die 
Zeiteinbeit a mal grosser wablen und wir sagen von jeder Grosse, welcbe 
durch eine Zabl von dieser Eigenscbaft ausgedriickt wird, sie babe die 
Dimension einer Zeit. Die Gescbwindigkeit wird durcb den Quotienten 
zweier Zablen gemessen, wovon der Zahler die Dimension einer Lange, 
der Nenner die einer Zeit hat. Sie ist also sowohl von der Wabl der 



Zweite Vorlesung. 289 

Langen als auch von der Zeiteinheit abhangig, und wird a mal kleiner, 
wenn die erstere a mal grosser, dagegen a mal grosser, wenn die letztere 
a mal grosser gewahlt wird. Wir sagen daher ihre Dimensionen sind : 
Lange dividirt durch Zeit, was aber hiemit jeder geheimnisvollen oder 
metaphysischen Bedeutung eutkleidet ist. Man redet vielfaoh statt von 
dem Quotienten der Zalil welche die Zeit ausdriickt in die, welche die 
Lange ausdriickt, einfacli von dem Quotienten einer Zeit, in eine Lange. 
Man hat da den Begriff der Division erweitert und muss den Quotienten 
einer Zeit in eine Lange ganz neu definiren, geradeso wie man den Begriff 
einer negativen oder gebrochenen Potenz neu definirt und darunter einen 
Bruch respektive eine Wurzel versteht. Der Vortlieil dieser neuen Defi- 
nition besteht darin, dass man vielfach Rechnungsregeln, Tvelcbe fiir die 
friihere Definition bewiesen wurden auf die neue Definition iibertragen 
kann. Man darf aber nicht a priori schliessen, dass dies von alien Rech- 
nungsregeln gilt ; es muss vielmehr die Ubertragbarkeit von jeder Rech- 
nungsregel besonders bewiesen werden. Ebenso ist es eine vollstandig 
neue Definition, wenn wir unter der zweiten oder dritten Potenz eines Cen- 
timeters die geometrische Figur eines Quadrats oder Wtirfels von 1 cm. 
Seitenlange verstehen und es muss gerechtfertigt werden, in wie weit 
diese neue Definition zweckmassig ist. Die Fixirung des Begriffs der 
Beschleunigung und ihrer Componenten nach den drei Coordinaten- 
richtungen hat nun nicht mehr die mindeste Schwierigkeit. Sei A der 
Vector, welcher in Grosse und Richtung die Geschwindigkeit zur Zeit 
t, OB der, welcher sie zur Zeit t + Bt darstellt. Wir ziehen die Gerade 
CD, also die Differenz der beiden Vectoren. Dieselbe wird sehr klein 
sein, wenn St sehr klein ist. Wir erhalten aber eine endlich bleibende 
Gerade, wenn wir sie im Verhaltnis der Zeiteinheit zur Zeit St vergross- 
ern, wobei ihre Richtung unverandert bleiben soil. Die Grenze, welcher 
sich der so vergrosserte Vector CD mit abnehmendem St nahert, heisst 
der Beschleunigungsvector, seine Lange stellt die Grosse, seine Richtung 
die Richtung der Beschleunigung dar. Seine Componenten in den drei 
Coordinatenrichtungen heissen die Componenten der Beschleunigung. 
Man iiberzeugt sich in bekannter Weise, dass es die zweiten Ableitungen 
der friiher mit Xi "^' "^ bezeichneten Functionen sind. Wir miissen 
daher die Voraussetzung machen, dass diese Functionen auch zweite 
Ableitungen haben. Man iiberzeugt sich auch leicht, dass die Zahl, 
welche die Grosse der Beschleunigung ausdriickt wieder sowohl von den 
gewahlten Langen als von der gewahlten Zeiteinheit abhangt und a mal 



290 Ludwig Boltzmann : 

kleiner wird, wenn erstere a mal so gross, dagegen c^ mal grosser, wenn 
die Zeiteinheit a mal so gross gewahlt wird. Wir werden daher sagen, 
die Beschleunigung hat die Dimensionen : Lange dividirt durch das 
Quadrat der Zeit. Wir konnen wieder die Beschleunigung als solche 
definiren als den Quotienten einer Zeit in eine Geschwindigkeit oder des 
Quadrats einer Zeit in eine Lange ; diirfen aber die letzteren Defini- 
tionen nur mit einer gewissen Vorsicht anwenden, da sie Erweiterungen 
des Begriffs der aUgebraischen Division darstellen, fiir welche die An- 
wendbarkeit der verschiedenen in der Algebra bewiesenen Rechnungs- 
regeln erst neu erprobt werden muss. 

Nachdem wir diese Begriffe moglichst an die Erfahrung anknlipfend 
entwickelt haben, miissen wir zur Aufstellung der Gesetze iibergehn, 
nach welchen die Bewegung der Korper geschieht. Wir werden da 
natiirlich wieder nicht mit Aufstellung der Gesetze fiir die Bewegung 
eines materiellen Punktes beginnen, da dieser eine reine Abstraction ist. 
Wir werden Mas natiirlich auch nicht der Illusion hingeben, dass wir ohne 
alle Abstractionen auskommen. Wir konnen nach meiner Ansicht nicht 
einen einzigen Satz aussagen, welcher wirklich nur eine reine Erfahrungs- 
thatsache ware. Die einfachsten Worte wie gelb, sllss, sauer etc., welche 
blosse Empfindungen anzugeben scheinen, drlicken schon Begriffe aus, 
die bereits aus vielen Erfahrungsthatsachen durch Abstraction gewonnen 
worden sind. Wenn Gothe sagt, die Erfahrung ist nur zur Halfte 
Erfahrung so will er mit diesem scheinbar paradoxen Satze sicher aus- 
driicken, das wir bei jeder begrifflichen Auffassung der Erfahrung oder 
Darstellung derselben durch Worte schon iiber die Erfahrung hinaus- 
gehen miissen. Die oft aufgestellte Forderung, dass die Naturwissen- 
schaft nie iiber die Erfahrung hinausgehen diirfe, soUte daher nach 
meiner Ansicht dahin ausgesprochen werden, dass man nie zu weit iiber 
die Erfahrung hinaus gehen diirfe und nur solche Abstractionen ein- 
fiihren soUe, die sich bald wieder an der Erfahrung priifen lassen. Wir 
werden auch nicht das Tragheitsgesetz an die Spitze stellen. Dieses mag 
theoretisch das einfachste Gesetz der Mechanik sein, physikalisch ist es 
keineswegs das einfachste, da es eine ganze Reihe von Abstractionen 
zur Voraussetzung hat, worauf ich schon friiher hingewiesen habe. Als 
die beiden physikalisch einfachsten FaUe erscheinen uns vielmehr erstens 
der der relativen Ruhe zweitens, der freie Fall eines schweren Korpers. 
Wie wir sahen, konnen wir einen Korper niemals ganz den aussern Ein- 
fliissen entziehen. Wenn nun solche Einfliisse vorhanden sind, von denen 



Zweite Vorlesung. 291 

jeder fiir sich allein eine Bewegung erzeugen wiirde, wenn aber unter dem 
vereinten Einflusse aller relative Ruhe gegen das Bezugssystem Platz 
greift, so sagen wir alle Ursachen der Relativbewegung compensiren sich. 
Ich konnte mich auch des gebrauchlichsten Ausdruckes bedienen, die 
Krafte halten sich das Gleichgewicht, allein ich will absichtlich die gewohn- 
ten Ausdrllcke vermeiden, weil wir mit denselben unwillkiirlich eine Menge 
von Vorstellungen verbinden, die sich dann, ohne dass wir es woUen, 
unkontrolirt in unsere Schlussweise einschmuggeln und so den Schein 
erwecken, als batten wir etwas bewiesen, was wir nur gemass unserer 
alten Denkgewohnheit und Ideenassociation ohne Begrilndung beigefiigt 
haben. Ich will ausserdem das Wort Kraft vermeiden, ehe ich gleich- 
zeitig auch von der Masse sprechen kann. Endlich betrachten wir hier 
nur die relative Bewegung. Es kann aber ein Korper relativ gegen 
seine Umgebung ruhen, ohne dass sich die auf ihn wirkenden Krafte das 
Gleichgewicht zu halten brauchen wie ein Korper, der relativ gegen einen 
mit Beschleunigung sich bewegenden Lift ruht. 

Wir betrachten nun einen bestimmten Fall, wo die Ursachen der 
relativen Bewegung compensirt sind. Ein schwerer Korper sei an einen 
dtinnen Faden aufgehiingt. Wir konnten da meinen, dass gar keine 
Beweguugsursachen vorhanden sind. Doch finden wir, dass sofort 
Bewegung eintritt, wenn wir den Faden entfernen. Es miissen also 
mindestens zwei Beweguugsursachen vorhanden gewesen sein, welche 
sich gegenseitig compensirten. 

Wenn wir die nach Entfernung des Fadens eintretende Bewegung 
analysiren, so finden wir, dass sie, wenn gewisse allgemeine Bedingungen 
erfiillt sind, sehr angenahert immer in derselben Weise vor sich geht. 
Diese allgemeinen Bedingungen sind folgende. Die Oberfliiche des 
Korpers darf nicht zu gross gegen dessen Gewicht sein, es darf keine 
heftige Luftbewegung um den Korper herum stattfinden, der Faden muss 
ohne Erschiitterung durchgeschnitten oder ruhig durch Verbrennung 
Oder sonst wie vernichtet worden sein. Dieselbe Bewegung tritt auch 
ein, wenn wir den Korper anfangs mit der Hand oder einer Zange oder 
einer sonstigen Vorrichtung halten und plotzlich ohne Erschiitterung 
sich selbst iiberlassen. Das Charakteristische aller dieser Anfangs- 
bedingungen besteht darin, dass sammtliche Punkte des Korpers in den 
ersten Momenten der Bewegung sehr kleine Geschwindigkeiten haben. 
Wir konnen daher annahernd voraussetzen, dass sammtliche Punkte des 
Korpers im ersten Momente der Bewegung keinerlei Anfangsgeschwindig- 



292 Ludwig Boltzmann: 

keit hatten. Wenn diese Bedingungen erf iillt sind, so lehrt die Erfahr- 
ung, dass der Korper stets fast genau nach denselben Gesetzen sicli 
bewegt, wo immer er in der Nahe der Erdoberflache sich selbst iiberlassen 
■worden sei. Die Bewegung bestimmen wir dabei natiixlich einstweilen 
relative gegen die Erde. Wenn wir uns nochi auf einen nicht zu grossen 
Theil der Erdoberflache beschranken, so ist auch die Richtung der 
Bewegung iiberall dieselbe ; es ist die des Fadens, der friiher den 
Korper trug. Die Erfahrung lehrt nun fiir diese Bewegung die folgen- 
den Gesetze. Erstens der Korper bewegt sich parallel zu sich selbst, d. h. 
alle Punkte desselben legen in gleichen Zeiten, gleiche und gleichgerich- 
tete Wege zuriick. Da also die Bahn filr jeden Punkt dieselbe ist, so 
kann man sie als die Bahn des ganzen Korpers bezeichnen. Zweitens, alle 
diese Wege sind geradlinig. Drittens, die Geschwindigkeit wachst fort- 
wahrend, die Beschleunigung ist jedoch iiberall, zu alien Zeiten und sogar 
fiir alle Korper dieselbe. Dass diese Gesetze in der Natur nur mit 
grosserer oder geringerer Annaherung realisirt sind, wurde bereits 
besprochen. 

Wir konnen nun dasselbe Experiment wiederholen, nur dass wir dem 
Korper im Momente, wo wir ihn sich selbst iiberlassen einen Stoss geben, 
oder sonst wie bewirken, dass er schon anfangs eine Geschwindigkeit hat. 
Da wir die Satze vom Schwerpunkt und der Drehung der Korper noch 
nicht kennen gelernt haben, so miissen wir uns dabei auf die Falle 
beschranken, wo sich der Korper wieder parallel zu sich selbst bewegt. 
Es wird dies zwar nicht immer eintreten und wir konnen die Bedingungen 
dafiir, dass es eintritt noch nicht angeben, aber in vielen Fallen wird 
dies stattfinden und diese Falle wollen wir vorlaufig allein betrachten. 
In alien diesen Fallen legen wieder alle Punkte des Korpers gleiche 
Bahnen zuriick, welche wir also als die Bahn des Korpers bezeichnen 
konnen. Die ganze Bewegung kann wieder dahin beschrieben werden, 
dass die Beschleunigung immer vertikal nach abwarts gerichtet und 
iiberall zu alien Zeiten und fiir alle Korper dieselbe ist. Da wir nun 
gesehen haben, dass die Bewegung, wenn wir sie an verschiedenen Stellen 
im Zimmer oder in dessen Umgebung beginnen lassen, immer in ganz 
gleicher Weise vor sich geht, so miissen wir schliessen, dass die Beweg- 
ungsursache, welche wir Kraft nennen, daselbst iiberall unveranderlich 
dieselbe ist. Anderseits ist auch die Beschleunigung unveranderlich 
dieselbe, wir konnen daher schliessen, dass wenigstens in diesem speziellen 
Falle die Beschleunigung das fiir die Kraft Massgebende ist und weil 



Dritte Vorlesung. 293 

erstere iiberall vertikal nach abwarts gerichtet ist, so sagen wir auf den 
Korper wirkt eine constante vertikal nach abwarts gerichtete Kraft die 
Sch-were. 

Dritte Voklesung. 

Um tiefer in die Gesetze der Bewegungen einzudringen, miissten wir 
jetzt die nachst einfachsten Falle betrachten. Ein naives Gemiit konnte 
da wohl meinen, dass wir nun die Gesetze nach denen ein Grashalm wachst, 
untersuchen sollten. Leider aber wissen wir iiber diese noch heute fast 
gar nichts. Besser ware es schon die Gesetze der Wirkung gespannter 
Schnlire, Federn etc. zu betrachten. Allein auch da treten die Beweg- 
ungsgesetze nicht in grosster Einfachheit hervor. Der historische Gang 
war viehnehr der folgende. Nachdem Galilei die Bewegungsgesetze 
soweit wir sie bisher betrachtet haben, gefunden hatte, suchte Newton 
sie yor allem auf die Bewegung der Gestirne anzuwenden und auch von 
ihm gilt, was Schiller von Wallenstein sagte: ^^Fiirwahr ihn hat kein 
Wahn betrogen als er auf warts zu den Sternen sah." Dem Laufe der 
Sterne hat er die Bewegungsgesetze abgelauscht, auf denen alle heute in 
der Technik und Machinenlehre benutzten Formeln ja iiberhaupt unsere 
ganze moderne Naturkenntnis basirt. Freilich bringt der Ubergang zur 
Sternenwelt manche Unbequemlichkeit mit sich. Erstens miissen wir 
um einfache Gesetze zu erhalten, unser altes Bewegungssystem, als welches 
der Erdkorper diente, verlassen und ein relativ gegen den Fixsternhimmel 
sich nicht drehendes Coordinatensystera wahlen. Zweitens ist auch die 
Bedingung, das die Planeten sich parallel zu sich selbst bewegen nicht 
erfiillt. An ihre Stelle tritt der Umstand, dass ihre Entfernungen vom 
Beobachter so gross sind, dass ihre einzelnen Theile iiberhaupt nur schwer 
unterschieden werden konnen, so dass wir also in der ersten Annaherung 
mit welcher wir uns wieder begniigen, iiberhaupt die Bahnen der ver- 
schiedenen Punkte eines und desselben Planeten gar nicht unterscheiden 
konnen. Wir konnen also wohl auch annehmen, dass die Gesetze dieselben 
waren, wenn die Himmelskorper sich parallel zu sich selbst bewegten. 
Wir kommen also hier einestheils dem Begriffe des materiellen Punktes 
sehr nahe, da die Ausdehnung der bewegten Korper so klein gegen die 
Lange ihrer Bahn ist, dass letztere fiir alle Punkte der Korpers merklich 
gleich wird. Anderseits aber sind wir von dieser Idee so weit entfernt 
als moglich, da wir es mit Korpern zu thun haben, die nichts weniger als 
materielle Punkte, vielmehr oft grosser als unser ganzer Erdkorper sind. 



294 Ludivig Boltzmann: 

Die Beobachtung und Messung lehrt, dass sich im Weltraume haufig 

um einen Centralkorper ein System von Himmelskorpern bewegt, welche 

wir die Trabanten nennen. Wir erhalten die einfachsten Gesetze, wenn 

wir die Bewegung der Trabanten auf ein Coordinatensystem beziehen, 

dessen Anfangspunkt im Mittelpunkte des betreffenden Centralkorpers 

liegt und dessen Axen dreien fest mit dem Fixsternhimmel verbundenen 

Geraden stets parallel bleiben. Fiir die Bewegung der Trabanten gelten 

erfahrungsgemass die drei Keppler'scben Gesetze. Da beim freien Falls 

die Beschleunigung eine so wichtige RoUe spielte, so wollen wir auch 

in diesem Falle die Beschleunigung berechnen, welche irgend ein Tra- 

bant in seiner Bewegung erfahrt. Diese Rechung ist sehr bekannt und 

ganz leicht. Es hat sie Kirchhoff in seinen Vorlesungen iiber Mechanik 

in sehr eleganter Form durchgefillirt. Man findet aus dem ersten und 

zweiten Keppler'schen Gesetze, dass sie fiir jeden Trabanten zu jeder Zeit 

gegen den Centralkorper gerichtet und dem Quadrate des Abstandes r 

k 
von demselben verkehrt proportional, also in der Form — darstellbar ist. 

Aus dem dritten Keppler'schen Gesetze ergibt sich ausserdem, dass die 
Constante k von Centralkorper zu Centralkorper verschieden ist, aber 
fiir alle Trabanten eines und desselben Centralkorpers denselben Wert 
hat. Da wir schon bei der Schwere die Beschleunigung als das mass- 
gebende fiir die Bewegungsursache oder Kraft erkannt haben, so 
wollen wir auch hier sagen, der Centralkorper iibt auf jeden Trabanten 
eine Kraft aus, welche die Richtung der vom Mittelpunkte des Trabanten 
gegen den des Centralkorpers gezogenen Geraden hat und der Lange 
dieser Geraden verkehrt proportional ist. Diese ist einstweUen sonst 
nichts als ein anderer Ausdruck fiir die Thatsache des VorhandenseLns 
dieser Beschleunigung. Newton hat diesen Satz sofort enorm verallge- 
meinert indem er annahm, dass iiberhaupt jeder Hiramelskorper auf jeden 
andern ja jedes materielle Theilchen auf jedes andere eine solche Kraft 
ausiibt. Wenn daher ein Himmelskorper mehreren andern so nahe ist, 
dass er von ihnen eine merkliche Einwirkung erfahrt, so haben wir den 
Fall, dass er gleichzeitig aus verschiedenen Ursachen verschiedene Be- 
schleunigungen nach verschiedenen Richtungen erfahrt. Da wir die 
Beschleunigung durch einen Vector dargestellt haben, so ist es nicht die 
einzig notwendige, aber doch bei weitem die nahe liegendste, einfachste 
Annahme, dass sich diese Beschleunigungen wie Vectoren addiren. In 
der That zeigt sich, dass man unter dieser Annahme immer Ubereinstim- 



Dritte Vorlesung. 295 

mung mit der Erfahrung erhalt. Es ergeben sich die Storungen der Plane- 
ten untereinander, der Monde durch die Sonne und durch die Planeten in 
genauer Ubereinstimmung mit der Erfahrung. Man kann jetzt auch den 
Horizont erweitern und alle Himmelskorper auf ein und dasselbe mit 
dem Fixsternhimmel fest verbundene Coordinatensystem beziehen und 
erhalt auch die Bewegung der Centralkorper gegen dieses Coordinaten- 
system in Ubereinstimmung mit der Erfahrung. Die Schwere erweist 
sich als identisch mit der Anziehung des Erdkorpers auf den schweren 
Korper. Schliesslich zeigen die Erscheinungen der Ebbe und Flut, die 
Versuche von Cavendish, Maskelyne, Airy etc. die Richtigkeit der Aus- 
dehnung des Newton'schen Gesetzes auf die irdischen Korper. Da die 
wirkliche Beschleunigung immer die Vectorsumme der verschiedenen 
von den wirkenden Korpern erzeugten Beschleunigung ist, so folgt jetzt 
als spezieller Fall des Newton'schen Gesetzes, dass ein Korper, welcher 
von alien llbrigen so weit entfernt ware, dass keiner derselben eine Wirk- 
ung auf ihn ausliben wiirde, zu alien Zeiten die Beschleunigung Null 
erflihre. Wir erhalten also erst jetzt das Tragheitsgesetz. Selbstver- 
standlich ist hiemit iiber die Ursache der Newton'schen Kraft, ob die- 
selbe eine direkte Fernwirkung ist oder durch ein Medium vermittelt 
wird, nicht das mindeste prajudicirt. Wir konnten auch jetzt schon den 
Begriff der Masse ableiten. Die Massen zweier Centralkorper wilrden 
sich ja wie die ihnen entsprechenden Werte der Constanten h des Gravi- 
tationsgesetzes verhalten und durch den Cavendish'schen Versuch konnte 
diese Definition auch auf irdische Korper ausgedehnt werden. Allein wir 
wiirden da die Proportionalitat der Constante h mit der als Tragheits- 
widerstand definirten Masse vorwegnehmen, was offenbar ein logischer 
Fehler ware. Wir miissen daher zum Begriffe der Masse auf ganz an- 
derem Wege zu gelangen suchen. Wir haben bisher als das Massge- 
bende fiir die Kraft die Beschleunigung betrachtet. Es konnte nun als 
das einfachste erscheinen, die Grosse der Beschleunigung, welche ein 
Korper durch einen andern erfahrt, einfach als die Grosse der Kraft zu 
bezeichnen, welche der letztere auf den ersteren ausiibt. Es geschieht 
dies auch manches Mai und man bezeichnet die so definirte Kraft als die 
beschleunigende Kraft. Allein im AUgemeinen ist es besser einen andern 
Begriff einzufiihren. Wir denken namlich beim Worte Kraft in erster 
Linie an die Muskelanstrengungen, welche wir ausiiben konnen. Nun 
liegt freilich kein Grund vor, ja es ware ganz verkehrt anzunehmen, dass 
jedes Mai, wenn unbelebte Korper Krafte aufeinander ausiiben etwas 



296 Ludwig Boltzmann: 

vorhanden sein miisse, was diesen Muskelanstrengungen irgendwie ent- 
spricht. Allein es wird sich doch empfehlen, wenn wir die Bezeich- 
nungen so wahlen, dass sie sich den durch diese Muskelanstrengungen 
erworbenen Begriffen moglichst gut anschliessen. Wir sahen, dass alle 
Korper durch die Schwere die gleiche Beschleunigung erf ahren. Wiirden 
wir nun diese ohne weiteren Factor als Mass der Kraft wahlen, so ware 
die Kraft, welche die Schwere auf sie ausiibt, (das Gewicht) fiir alle 
Korper dasselbe. Nun lehrt aber die tagliche Erfahrung, dass die Mus- 
kelanstrengung welche wir brauchen, um den Fall aufzuheben, fiir ver- 
schiedene Korper sehr verschieden ist. Wollen wir daher mit unseren Vor- 
stellungen im Einklang bleiben, so miissen wir sagen, dass auch die Schwere 
auf die verschiedenen Korper sehr verschiedene Krafte ausiibt, dass aber 
die Korper von grosserem Gewichte dieser beschleunigenden Wirkung der 
Schwere einen grosseren Widerstand, den Tragheitswiderstand, die Masse, 
entgegensetzen, so dass erst in folge beider Umstande zusammen alle 
Korper die gleiche Beschleunigung erfahren. Um die Masse in dieser 
Weise als Tragheitswiderstand zu definiren, miissen wir an verschiedene 
Korper die gleiche Kraft anbringen. Das Verbal tnis ihrer Massen kon- 
nen wir dann als das verkehrte Verhaltnis der Beschleunigungen defi- 
niren, die sie durch gleiche Krafte erhalten. Aber darin liegt eben die 
grosste Schwierigkeit wie man die Gleichheit der Krafte, wenn diese auf 
verschiedene Korper wirken, ohne logischen Fehler feststellen soil. Man 
konnte zwei Korper dem Zuge gleich beschaffener gleich gespannter 
Schniire oder elastischer Federn unterwerfen. Allein da miisste man 
erst durch complicirte der Erfahrung entnommene Argumente als wahr- 
scheinlich hinzustellen suchen, dass gleich beschaffene Schniire auf zwei 
ganz verschiedene Korper dieselben Krafte ausiiben, was gewiss nicht 
a priori evident ist. Wir konnten auch nach Mach einfach den Satz 
der Gleichheit der Wirkung und Gegenwirkung postuliren. Wenn dann 
bloss zwei Korper in Wechselwirkung begriffen sind, so ware die Gleich- 
heit der Krafte, welche auf beide Korper wirken evident. Wenn sie sich 
zudem nur Parallelverschiebungen ertheilen, so ware das Verhaltnis 
ihrer Massen einfach zu definiren, als das verkehrte Verhaltnis der Be- 
schleunigungen, welche an ihnen zu beobachten sind. Allein bei der 
Wirkung dazwischen gebrachter Schniire, Faden etc. haben wir eigent- 
lich schon immer mehr als zwei in Wechselwirkung begriffeue Korper 
und es wlirde auch die Deformation dieser Zwischenkorper in Betracht 
zu Ziehen sein. Der von Mach angenomraene Fall konnte also in reiner 



Dritte Vorlesung. 297 

Weise eigentlich nur bei directer Fernwirkung vorkommen und es ware 
sehr misslich, wenn man vom rein empirischen Standpunkte aus die 
directe Fernwirkung a priori annehmen mlisste. Streintz sucht eine 
einwurfsfreie Detinition in folgender Weise zu gewinnen. Er denkt 
sicli irgend ein System beliebiger Korper. In demselben kommen zwei 
Korper K^ und K^ vor. Diese ruhen im ersten Augenblicke und beginnen 
sich dann mit Besohleunigung aber jeder parallel zu sicli selbst zu be- 
wegen. Es soil nun die Bewegung beider Korper dadurcli aufgehoben 
werden konnen, dass man sie starr mit einander verbindet. Dies ver- 
wendet er als Kriterium, dass friiher auf jeden genau die gleiche Kraft 
wirkte, weil sich beide Krafte durch blosse starre Verbindung jetzt auf- 
heben. Er nennt diese Begriffsbestimmung der Gleichheit der Kraft die 
statische. Sie hat das fiir sich, dass sie das Princip der Gleichheit der 
Wirkung und Gegenwirkung involvirt, wie man sofort sieht, wenn man 
den speziellen Fall betrachtet, dass das ganze System bloss aus den zwei 
auf einander wirkenden Korpern K^ und K,^. besteht. Sie hat aber doch 
auch manches Willkiirliche. Dass durch die starre Verbindung die Wirk- 
ung der librigen Krafte nicht gestort wird, kann wieder hochstens 
erfalirungsmassig wahrscheinlich gemacht werden. Dass die Verbin- 
dungskrafte sich zu den iibrigen addiren, setzt schon gewisse Satze der 
Statik voraus. Noch grosser wiirden die Schwierigkeiten, wenn, die 
Korper K-^ und K^ anfangs in Bewegung begriffen waren. WoUte man 
da nicht von vornherein annehmen, dass die Krafte bloss von der rela- 
tiven Lage abhangen, durch den aus der plotzlichen starren Verbindung 
resultirenden Stoss nicht gestort werden und Ahnliches, so mtisste ihre 
Beschleunigung durch eine die Bewegung gestattende und auf beide 
Korper bloss beschleunigend wirkende plotzlich eingeschaltete Feder 
aufgehoben werden. Halt man einmal an der Streintz'schen Vorstellung 
fest, so hat die Definition der Massenverhaltnisses welter keine Schwierig- 
keit. Die Massen der beiden Korper K^ und K^ verhalten sich dann 
umgekehrt, wie die Beschleunigungen, die sie im ersten Falle, wo keine 
starre Verbindung vorhanden war, erhielten, da ja damals auf beide 
gleiche Krafte wirkten. Natllrlich ist sowohl bei der Mach'schen als bei 
der Streintz'schen Definition noch immer erforderlich, sich auf besondere 
Erfahrungssatze zu berufen, vermoge welcher das Massenverhaltnis 
zweier Korper immer gleich ausfallt, unter was immer fiir Umstanden 
man den hiezu dienenden Versuch angestellt haben mag und vermoge 
welcher das Verhaltnis der Massen der Korper K-^ and K^ stets gleich 



298 Ludwig Boltzmann: 

dem Producte der beiden Massenverhaltnisse der Korper K^, K^ und K^, 
Ks ist. 

Zu bemerken ist noch, dass wir nur das Verhaltnis zweier Massen bisher 
definirt haben. Um die Masse durch eine Zahl auszudriicken, miissen 
wir irgend eine Masse willkiirlich als eine neue Einheit wahlen. Von 
alien Grossen, welche daher durch Zahlen ausgedriickt werden, deren 
Grosse von der Wahl der Masseneinheit abhangig ist, werden wir sagen 
dass sie gewisse Dimensionen beziiglich der Masse haben. Haben wir den 
Begriff der Masse in der einen oder andern Weise festgestellt, so hat die 
Definition der Kraft im gewohnlichen Sinne oder wie man auch sagt, der 
bewegenden Kraft keine Schwierigkeit mehr. Dieselbe ist das Product 
der Masse in die Beschleunigungen und hat daher beziiglich der Masse 
die Dimension eins. Da sich die Beschleunigungen wie Vectoren addi- 
ren, so gilt dies auch von den Kraften, wenigstens insoweit wir diese 
bisher betrachtet haben. Dieser Satz vom Kraftenparallelogramm sowie 
die iibrigen bisher entwickelten Satze, konnen nun auch auf die Statik 
und Dynamik der durch gespannte Faden oder durch Federn erzeugten 
Druck und Zugkrafte iibertragen werden. Natiirlich zunachst bloss in 
dem idealen Falle, dass die Bewegung der einzelnen Theile der Faden und 
Federn nicht betrachtet wird und dass die bewegten Korper sich stets 
parallel zu sich selbst bewegen. Es konnte so z. B. die Mechanik der 
Atwood'schen Fallmaschine mit Hilfe des bisher Entwickelten ohne 
weiteres discutirt werden. 

Aus dem Umstande, dass sich das Newton'sche Gravitationsgesetz in 
symetrischer Weise beziiglich beider wirkender Korper aussprechen muss 
und dass die Anziehungsconstante K fiir alle Trabanten desselben Cen- 
tralkorpers gleich ist, leitet man leicht ab, dass diese gleich dem Producte 
der Massen der beiden wirkenden Korper in eine fiir das ganze Universum 
constante Grosse sein muss, wahrend die Thatsache, dass alle Korper 
durch die Schwere die gleiche Beschleunigung erhalten, schon lehrt, dass 
das Gewicht der Masse proportional sein muss. 

Wir sind aber noch sehr weit davon entfernt aus den bisher entwickel- 
ten Grundlagen sammtliche Satze der Mechanik ableiten zu konnen. 
Wir haben ja bisher bloss die Bewegung eines festen Korpers parallel zu 
sich selbst betrachtet und haben den wichtigen Begriff des Angriffspunk- 
tes einer Kraft noch gar nicht gewonnen. Um diesen zu erhalten, um die 
Drehung der starren Korper, die Deformationen der elastischen und die 
Bewegungen der fliissigen behandeln zu konnen, miissen wir von neuen 



Dritte Vorlesung. 299 

Thatsachen ausgehen. Wenn ein Faden an einem Korper befestigt ist 
oder eine Feder auf eine einzige Stelle desselben driickend wirkt, so gibt 
es stets eine ganz kleine Partie des Korpers, welche zunachst von der 
Kraft afficirt wird. Losen wir diese los und stellen einen kleinen 
Zwischenraum zwischen ihr und den iibrigen Theilen des Korpers her, 
so wird derselbe erst wieder afficirt, wenn dieser Zwischenraum durch 
die Bewegung des kleinen abgetrennten Theiles sicli ausgeflillt hat. 
Wir nennen daher diesen Theil die Angriffstelle und konnen sie wieder 
zu einem Angriffspunkte idealisiren. Wir miissen nun noch die bekann- 
ten Satze iiber die Versetzbarkeit von Kraften an starren Korpern als 
idealisirte Erfahrungsthatsachen beifiigen. Mittelst derselben konnen 
wir dann in ebenfalls hinlanglich bekannter Weise die Satze iiber das 
Gleichgewicht von beliebigen Kraften, welche auf einen starren Korper 
wirken, die Satze von den statischen Momenten ableiten. Wir schlagen 
hier insoferne einen analogen Weg ein, wie Streintz bei der Definition 
der Masse, als wir von der Statik ausgehen und erst von dieser zur 
Dynamik gelangen. Die Satze von den statischen Momenten haben wir 
da freilich zunachst bloss ftir eine begrenzte Zahl von Kraften bewiesen, 
von denen jede nur auf einen einzelnen Punkt des Korpers wirkt. Wir 
miissen dazu noch die Annahme hinzufiigen, dass man im Falle, wo die 
Krafte den Korper oder einen ausgedehnten Theil desselben als Ganzes 
anfassen die Sache immer so ansehen kann, als ob sie auf sehr viele 
respective unendlich viele Punkte seiner Oberflache oder seines Innern 
gerade so wirken wiirden, als ob an jedem dieser Punkte eine ein wenig 
gespannte Schnur oder eine ein wenig driickende Feder befestigt ware. 
So muss mann z. B. von der Schwere annehmen, das sie gleichmassig 
auf alle Punkte des schweren Korpers wirkt. Einen andere Weg, auf 
welchem man den Ubergang von der Bewegung parallel zu sich selbst 
zur Drehbewegung versuchen konnte, will ich hier nur ganz kurz 
andeuten. Wir konnen aus dem Principe der Erhaltung der lebendigen 
Kraft folgenden Satz ableiten. Wenn auf einen festen Korper eine Kraft 
wirkt, die ihn nur parallel zu sich selbst zu bewegen sucht, so muss 
immer eine ihrer Richtung parallele Gerade, welche wir die Angriffslinie 
nennen woUen, von solcher Beschaffenheit existiren, dass wenn man einen 
beliebigen Punkt des festen Korpers, welcher auf derselben liegt, festhalt, 
der Korper ins Gleichgewicht kommen muss. In gleicher Weise kann 
man beweisen, dass, wenn zwei feste Korper K^ und K^^ so in Wechsel- 
wirkung begriffen sind, dass jeder dem andern nur eine Bewegung parallel 



300 Luchvig Boltzmann : 

zu sich selbst ertlieilt, Wirkung unci Gegenwirkung gleich sein muss und 
die Angriffslinien zusammenfallen miissen. Denkt man sich dann einen 
Punkt A der gemeinsamen Angriffslinien festgehalten, so muss das ganze 
System ins Gleichgewicht kommen. Jeden solchen Punkt konnen wir als 
Angriffspunkt der Kraft betrachten. An diesen Begriff des Angriffs- 
punktes, konnen dann ebenfalls die Satze von den statiscben Momenten 
gekniipft werden. 

Hat man einmal diese Satze so oder so gewonnen, so muss man zur 
Zerlegbarkeit der Korper in Volumelemente llbergeben. Man fiihrt 
wieder als Erfahrungssatz an, dass sehr viele Korper, wenigstens mit 
geniigender Annaberung in zwei Korper von je der balben Masse zerlegt 
werden, wenn man sie in zwei Tbeile von gleicbem Volumen zerschneidet. 
Analog, wenn man sie in drei gleicbe Tbeile tbeilt u. s. f. Denkt man 
sicb dies ins Unendlicbe fortgesetzt, so gelangt man zu einem Satze, 
den man dabin aussprecben kann dass diese Korper aus unendlicb vielen 
Volumelementen dv besteben und die in jedem Volumelemente entbaltene 
Masse dm = pdv ist. Bei andern inbomogenen Korpern gilt dies wenig- 
stens nabezu fiir jeden kleinen Volumtbeil des Korpers, so dass wir die- 
selbe Formel anwenden konnen, wenn wir p als von Punkt zu Punkt 
veranderlicb betracbten. 

Was nun die Krafte anbelangt, welcbe die Volumelemente fester 
Korper aufeinander ausiiben, so muss man aunebmen, dass jedes Volum- 
element nur auf die unmittelbar benaebbarten wirkt und dass es auf alle 
der Trennungsflacbe anliegenden Punkte Krafte ausilbt, welcbe gerade 
so wirken, als ob daran ziebende gespannte Faden oder drilckende, auf- 
gestiitzte Stiibe befestigt waren. Wenn die Trennungsflacbe eben und 
geniigend klein ist, so muss man zudem annebmen, dass diese Krafte 
gleichmiissig auf alle der Trennungsflacbe anliegenden Punkte wirken. 
Diese Satze konnen wol kaum direct erfahrungsmassig bestatigt werden 
und finden ihre Recbtfertigung nur in der nacbberigen Ubereinstimmung 
der aus ibnen entwickelten Satze mit der Erfabrung. Wendet man den 
Satz von den statiscben Momenten auf ein Volumelement an, so findet 
man, dass im Falle des Gleicbgewicbtes die auf ein zur a;-axe senkrecbtes 
Flacbenelement in der y-Ricbtung wirkende Kraft gleich sein muss der 
auf ein gleicbes zur ?/-Richtung senkrecbtes Flacbenelement in der 
2;-Richtung wirkenden Kraft, was wir den Satz X nennen woUen. Zu 
den bisber aufgestellten Annabmen welcbe wir uns als durcb die Erfabr- 
ung geniigend motivirt dacbten, sind nocb die folgenden binzuzunehmen. 



Dritte Vorlesung. 301 

Erstens, die elastische Kraft ist bloss von der augenblicklichen Gestaltver- 
anderung des betreffenden Korpers, nicht von den friilieren Zustanden 
desselben, noch auch von der Geschwindigkeit seiner Theilchen abhangig. 
Zweitens, jedes Volumelement bewegt sich nacb den Gesetzen, welche wir 
bislier bloss fiir die Bewegung parallel zu sich selbst abgeleitet haben. 
Unter diesen Annahmen erhalt man dann sofort die Gleichungen der 
gewohnlicben Elasticitatslehre. Dieselben gelten natiirlich wieder nur 
fiir einen idealen festen Korper, alle festen Korper zeigen innere Reibung 
und elastische Nachwirkung, welche wir bisher ausgeschlossen haben. 
Auch der Satz, welchen wir den Satz X nannten, ist keineswegs a priori 
evident. Lord Kelvin hat sich einmal den Lichtather, sonst ganz mit den 
Eigenschaften begabt gedacht, welche wir an festen Korpern wahrnehmen, 
nur dass er die Richtigkeit dieses Satzes X fallen liess. Wir woUen uns 
hier nicht in eine Discussion einlassen ob durch die Annahme Lord 
Kelvins das Verhalten des Lichtathers erklart werden kann. Es geniigt 
uns, dass derselbe ohne alle inneren Widersprliche Bewegungsgleichungen 
fiir die Volumelemente eines festen Korpers ausarbeiten konnte, fiir 
welchen der Satz X nicht gilt. Wir woUen jedoch vorlaufig bei Korpern 
stehen bleiben, welche den idealen Gleichungen der Elasticitatslehre 
geniigen. Wenn solche Korper so wenig deformirbar sind, dass man sie 
als Starr betrachten kann und wenn durch beliebige Systeme derselben 
beliebige Bedingungsgleichungen realisirt sind, so kann man jetzt leicht 
nachweisen, dass fiir dieselben das vereinigte Princip der virtuellen 
Geschwindigkeiten und d'Alembert's gelten muss. Denn wenn man 
alle Krafte auch die elastischen ins Auge fasst, so verschwindet jedenfalls 
die Summe 

.g-x)...(™g-r)%+(,.g-^)8.]. 

da jedes Glied dieser Summe einzeln verschwindet. Da aber die Wirkung 
immer gleich der Gegenwirkung ist, so miissen die Glieder dieser Summe, 
welche sich auf die Wechselwirkung der Volumelemente beziehen separat 
verschwinden, wenn diese starren Korpern angehoren also keiner relativen 
Lagenanderung fahig sind, wahrend bei bloss einseitigen Verbindungen 
die bekannten Ungleichungen abgeleitet werden konnen. Dies kann 
auch auf Verbindungen iibertragen werden, die nur theilweise starr sind 
z. B. unausdehnsame Flachen, Faden etc. ; denn diese konnen immer als 
Grenzfall sehr diinner elastischer Korper betrachtet werden. Man erhalt 



![' 



302 Ludwig Boltzmann : 

so das vereinigte Princip der virtuellen Verschiebungen und d'Alembert's 
in der gewoKnliclien Form. Erst aus diesem Principe konnen wir jetzt 
die Satze von der Bewegung des Schwerpunkts, vom Tragheitsmomente 
etc. ableiten. Diese Satze erscheinen daher in unserem Systeme erst an 
dieser Stelle. Es kann dies nicht anders sein ; denn darin bestebt ja das 
Wesen der inductiven Methode, dass wir nicbt den Begriff des materiellen 
Punktes als eines unausgedebnten mit Masse begabten Korpers postuliren, 
sondern die Scbliisse, welcbe man sonst mit Hilfe dieses Begriffes macbt, 
erst ausf iibren, wenn wir zur Vorstellung des Volumelementes gekommen 
sind, welcbe wir eber der Erfabrung entnebmen zu konnen glauben, als 
die des materiellen Punktes. Wir konnen dann diese Siitze erst erbalten, 
wenn wir die Wecbselwirkung der Volumelemente bebandelt baben. 
Wir mussten freilicb sebon friiber an zwei Stellen vom Begriffe des 
matbematiscben Punktes Gebraucb macben, namlicb als wir die Beweg- 
ung eines einzigen bervorgebobenen Punktes eines Korpers betracbteten 
und als wir Krafte fingirten, welcbe an einem einzigen Punkte eines 
Korpers angreifen. AUein da war die Abstraction docb viel einfacber 
und klarer, als wenn wir das Ideal eines unausgedebnten mit Masse 
begabten Korpers bilden und dessen Drebung einfacb vernacblassigen, 
obne dass wir die Gesetze der Drebung vorber kennen gelernt baben. 
Mancbe Satze konnten wir allerdings aucb auf einem audern als dem 
eingescblagenen Wege gewinnen. Ein Analogon des Scbwerpunktsatzes 
konnten wir z. B. ableiten, indem wir ein System von ausgedebnten 
Korpern betracbten wiirden, zwischen denen innere Krafte tbatig sind 
und auf welcbe aucb aussere Krafte wir ken, welcbe ibnen aber aUe nur 
Bewegungen parallel zu sicb selbst ertbeilen. Nimmt man dazu nocb die 
Annabme, dass fiir die innere Krafte Wirkung und Gegenwirkung immer 
gleicb ist, so wiirde ein dem Scbwerpunktsatze abnlicber Satz fiir ein 
solcbes System in Wecbselwirkung begriffener ausgedebnter Korper 
folgen. 

Die Krafte, welcbe in Fliissigkeiten wirken, konnen als ein spezieUer 
Fall, der in elastiscben Korpern wirkenden betracbtet werden und sie 
konnen daber ebenfalls nacb der im bisberigen auseinandergesetzten 
Metbode gewonnen werden. Die Gestaltanderungen der Fliissigkeiten 
konnen dann durcb die Bewegung der Volumtbeile derselben dargestellt 
werden, welcbe die entwickelten Gesetze bef olgt ; nur dass die Deforma- 
tion des Korpers als Gauzes jetzt eine beliebig grosse sein kann. 

Wir baben biemit das Gebiet der eigentlichen mecbaniscben Erscbein- 



Dritte Vorlesung. 303 

ungen erschopft. Bei den dissipativen Erscheinungen (elastische Nach- 
wirkung, Reibung etc.) spielt bereits die entwickelte Warme eine RoUe. 
Wir konnen natiirlich die Form der friihern Gleichungen wahren, indem 
wir zu den bisher abgeleiteten Kraften noch Glieder von soldier Be- 
schaffenheit hinzu addiren, dass deren Summe genau gleich dem Werte 
der mit der Masse multiplicirten Besclileunigung wird. Diese Zusatz- 
glieder konnen wir dann immer als Reibungskraft, Mittelswiderstands- 
kraft etc. bezeichnen, doch hat diese Darstellung einen rein formalen 
Wert, wenn die Zusatzglieder in ganz complicirter Weise von der 
Bewegungsgeschwindigkeit, den friihern Zustanden etc. abhangen. Es 
bietet die Molekulartheorie da entschieden mehr Anschaulichkeit, da sie 
die Zusatzglieder doch durch langsame Drehung der Moleklile in neue 
Ruhelagen, Umsetzung der sichtbaren Bewegung in Molekularbewegung 
etc. einigermassen versinnlichen kann. Das Princip der virtuellen Ver- 
schiebung behalt dann natiirlich, so lange es auf das Gleichgewicht 
ruhender Korper angewendet wird, seinen Sinn, da bei der Ruhe dissipa- 
tive Vorgange fehlen. Aber das d'Alembert'sche Princip ist audi zu 
einer leeren Forniel herabgesunken, so bald sich in den Ausdriicken fiir 
die Krafte Glieder finden, welche selbst wieder von der Bewegung, von 
den vorhergegangenen Zustanden der Korper etc. abhangen. Uber die 
Darstellung der elektrischen und magnetischen Erscheinungen will ich 
hier nur bemerken, dass dieselbe ebenfalls in die Form der mechanischen 
Gleichungen gebracht werden kann und muss, sobald diese Erscheinungen 
von Bewegungen ponderabler Korper begleitet sind. Des Naheren hier- 
auf einzugehn, ist jedoch niclit meine Absicht. 

Ich woUte in dem Bisherigen keineswegs eine consequente in sich 
abgeschlossene Darstellung der Mechanik vom inductiven Standpunkt 
geben. Ich woUte vielmehr bloss die Wege andeuten, auf denen eine 
solche vielleicht gewonnen werden konnte und namentlich die Schwierig- 
keiten aufdecken, mit denen ihre Durchfiihrung verkniipft ist, wenn man 
sich bestrebt, das innere Bild ebenso klar hervortreten zu lassen und 
consequent durchzufiihren, wie dieses bei der deductiven Behandlung 
moglich ist. Ich komme daher zu dem Resultate, dass unter den bis- 
herigen Darstellungsversuchen der Mechanik die deductiven, wie die von 
Hertz und die von mir in meinem citirten Buche gemachte vorzuziehen 
seien. Da aber diese deductive Darstellung wie schon zu Anfang 
gezeigt wurde, den Mangel hat, dass sie so lange Zeit hindurch gar 
nicht an die Erfahrung ankniipft und vielfach den Schein des Willkiir- 



304 



Ludwig Boltzmann . 



lichen erweckt, so wiirde es mich sehr freuen, wenn es jemanden gelange, 
der deductiven Darstellung eine inductive an die Seite zu stellen, welche 




gleich einfach und naturgemass vorginge und docli das innere geistige 
Bild in gleicher Deutlichkeit und Consequenz hervortreten liesse. Es 



Vierte Vorlesung. 305 

ware dies wohl in einer kurzen Abhandlung kaum moglicli, soiidern nur in 
einem grosseren Buche, wo man den Grundprincipien sogleicli die An- 
wendung auf alle speziellen Falle folgen lassen konnte. Denn erst an der 
Moglichkeit der exacten Darstellung aller moglichen speziellen Falle 
erprobt sich die Klarheit und Consequenz der Bilder, wie sich das am 
besten an der Hertz'schen Darstellung zeigt, wo diese Anwendung auf 
spezielle Falle fehlt. SoUten sich aber die Liicken, die sich in meiner 
gegenwartigen Darstellung finden, nicht ausfiillen lassen, so wlirde mich 
auch dies freuen, denn es wiirde den definitiven Sieg der deductiven liber 
die inductive Behandlungsweise bedeuten. Ich mochte gewissermassen 
die Vertreter der inductiven Richtung einladen, alle Fehler, die sich in 
meiner gegenwartigen Darstellung finden aufzudecken, die Moglich- 
keit der genauen Durchfiihrung aller Schlussweisen, die ich hier nur 
kurz angedeutet habe, zu zeigen und ihre bosten Krafte einzusetzen in 
dem Wettkampfe mit der deductiven Darstellung, damit beide mit ein- 
ander verglichen werden konnen und sich im Wettstreite stets ausbilden 
und vervoUkommnen. 

Da der Energiebegriff nicht nur in der Mechanik, sondern in der 
ganzen Naturwissenschaft eine so wichtige Rolle spielt, so waren auch con- 
sequente Darstellungen der Grundprincipe der Mechanik vom Standpunkte 
der Energetik hochst erwiinscht, welche also nicht von den Begriffen der 
Beschleunigung und Kraft sondern von denen der lebendigen Kraft und 
des Potentiales auszugehen hatten. Doch miissten die betreffenden 
Bilder auch nach der deductiven oder inductiven Methode durchaus klar 
consequent und einwurfsfrei entwickelt werden und es miissten voUkom- 
men pracise Regeln gegeben werden, wie dieselben eindeutig auf alle 
speziellen Falle anzuwenden sind, ohne dass die Kenntnis der alten 
Mechanik dabei vorausgesetzt wird. 

Vierte Voelesung. 

Die vierte Vorlesung begann der Vortragende mit der Vorzeigung des 
Modells fiir die Maxwell'sche Theorie der Elektricitat und des Magnetis- 
mus, welches in dessen Buch ^^Vorlesungen iiber Maxwells Theorie der 
Elektricitat und des Lichtes erster Theil " beschrieben ist. Es wurden 
alle dort erwiihnten Experimente mit giitem Erfolge durchgefiihrt. 
Hierauf gab er noch folgende Ubersicht iiber die das Princip der kleins- 
ten Wirkung und das Hamilton'sche Princip umfassenden Gleichungen. 



306 Imdwig Boltzmann: 

Wenn wir die Falle einseitiger Verbindungen ausschliessen, so wird 
das vereinigte Princip der virtuellen Verschiebimgen imd d'Alemberts, 
wie wir sahen durch eine Gleichung ausgedriickt, welche wir erhalten, 
wenn wir den Ausdriick auf Seite 36 gleich Null setzen. Flibrt man 
darin generalisirte Coordinaten ein und setzt Einfachheit halber voraus, 
dass eine Kraftfunction V besteht, welche aber die Zeit enthalten kann, 
so trausformirt sich dieselbe in folgende Gleichung 

dt dp dp 

wobei p irgend eine generalisirte Coordinate, q das dazu gehorige Mo- 
ment, T die gesammte kinetische Energie ist. Wenn jede beliebige 
Coordinate p zu jeder beliebigen Zeit t eine beliebige Variation Sp erfahrt, 
so kann man die letzte Gleichung mit Sp multipliciren und beziiglich aUer 
p summiren. Im speciellen Falle, dass alle Bp integrable Functionen der 
Zeit sind, kann man noch mit dt multipliciren und iiber eine beliebige 
Zeit (von t^ bis t} integriren ; nach partieUer Integration der dq/dt ent- 
haltenden GUeder f olgt in dieser Weise : 

^f\T- V)dt = ^iqhp - q.Sp,-) (1) 

wobei sich rechts die erstern Grossen auf die obere die letztern auf die 
untere Integrationsgrenze beziehen. 

1. Mamiltons Princip der stationdren WirJcung. 

Aus der Fundamentalgleichung 1) folgt das Princip der stationaren 
Wirkung, wenn man die Grenzen des Integrals und die Coordinaten- 
werte fiir dieselben als unveranderlich voraus setzt. Dann ergibt sich, 
wenn man setzt 

T-V=W, C'wdt^n, J^=w 

'A t- 1, 

folgende Gleichung : 

gn = Oder SF=0. 

O Oder Whaben also fiir die Bewegung dieselbe Bedeutung, wie F f iir 
das Gleichgewicht in der Ruhe. Die Bedingungen, welche den Grenz- 
wert von O oder W unter den geschilderten Umstanden angeben, sind 
mit den Bewegungsgleichungen identisch, wesshalb Helmholtz diese Gros- 



Vierte Vorlesung. 307 

sen als kinetisches Potential bezeichnet. Fiir das Gleichgewicht in der 
Ruhe, bestimmen diese Bedingungen einen Grenzwert von V, da dann 
2'= und Fvon der Zeit unabliangig ist. Der Satz, dass fiir das Gleich- 
gewicht, F'ein Grenzwert ist, ist also ein ganz specieller Fall des Satzes 
vom kinetische Potentiale oder des Hamilton' schen Princip der station- 
aren Wirkung, wie dieser aucb genannt wird. 

2. Hamiltons Princip der variirenden Wirkung. 

Wir setzen in Gleichung 1) einmal nur die untere dann nur die obere, 
dann nur den "Wert einer Coordinate fiir die untere, endlieh diesen 
Wert fiir die obere Grenze des Integrales als veranderlich voraus ; es 
folgen sofort die Hamilton'schen partiellen Differentialgleichungen : 

dt, dt dp, ^«' dp ^ 

Es soil nun V die Zeit nicht enthalten, also die Energie T+ V sicb mit 
der Zeit nicht andern. Wenn man dann in Gleichung 1) die Grenzen 
als variabel betrachtet, so transformirt man sie nach einigen Zwischen- 
rechnungen leicht in die folgende : 

2 8 f 2H« = fs ( y + F) c^i + 2 (^Sp - q^hp,) (2) 

wobei aber die Sp jetzt unter gleichzeitiger Variation der Grenzen fiir 
die Zeit und der Bewegung zu bilden sind. 



3. Das alte Princip der Meinsten Wirhung. 

Setzt man in Gleichung 2) die Coordinatenvariationen fiir die Gren- 
zen von t gleich Null und nimmt ausserdem an, dass die Variation der 
Bewegung ohne Energiezufuhr geschieht also 6(2'+ P^=0 ist, so folgt 



^j'Tdt = (), 



also die alte Form des Princips der kleinsten Wirkung, welches in 
mancher Beziehung specieller, in so fern aber wieder aUgemeiner ist, 
als das Princip der stationiiren Wirkung, als es die Bewegungszeit als 
veranderlich betrachtet. 



308 Ludwig Boltzmann: 

4. Analogien mit dem zweiten Hauptsatze. 

Wir woUen annehmen, class das letzte Glied der Gleichung 2) 
verschwindet. Es gilt dies nicht bloss, wenn an den Grenzen fiir die 
Zeit hp = S^g = ist, sondern auch wenn die Bewegung periodisch ist und 
t — t^ die Dauer dieser Periode ist. Es gilt auch wenn die Verschiebiingen 
sammtlicher materielleu Punkte des Systemes in folge der Variation der 
Bewegung senkrecht auf der augenblicklichen Geschwindigkeitsrichtung 
derselben steht. Bisher waren die Sp ganz willkiirliche Variationen. 
Wir woUen sie nun in folgender Weise erzeugt denken. 1. Mit dem 
Systeme, auf welches sich die Gleichung 2) bezieht, soil ein zweites Sys- 
tem verbunden sein, welches mit dem ersten in Wechselwirkung steht und 
letzteres soil eine unendlich kleine Bewegung machen. 2. Ausserdem 
soil dem ersten Systeme eine unendlich kleine lebendige Kraft ZQ zugefiihrt 
werden. Die in der Gleichung vorkommende Grosse h F'ist bloss die Veran- 
derung von F'in folge der Lagenanderung der Punkte des ersten Systems. 
Sei S'F'die in Folge der Lagenanderung des zweiten Systems, so ist ^'V 
die Arbeit der vom ersten auf das zweite System wirkenden Krafte. Sie 
muss mit der zugefiihrten Energie ^Q zusammen die gesammte Anderung 
hE der Energie des ersten Systems geben. Es ist also SJ?= hQ + h'V. 
Anderseits ist ^E= hT + hV + Z'V, da ST die Anderung der kinetischen, 
8F+8'Fdie Gesammtanderung der potentiellen Energie ist. Aus bei- 
den Gleichungen folgt hQ = h (^T + V). Setzen wir 

_ C^Qdt _ f'Tdt 
BQ = '^ und T = ^ , 

t — t^ t — tg 

so folgt aus Gleichung 2) unter den gemachten Annahmen sofort 



'-l=B\logn.t(£TdtJ] 



T L 

wo die Analogic mit dem zweiten Hauptsatze deutlich zu Tage tritt. 
Thermodynamisches Beispiel : Unter dem ersten Systeme verstehen wir 
die Molekiile eines Gases, unter dem zweiten einen das Gas begrenzenden 
beweglichen Stempel, hQ ist die dem Gase zugefiihrte Warme. Mechan- 
isches Beispiel : Das erste System ist ein mit einer punktformigen Masse 
verbundener Magnetpol der gezwungen ist, sich in einer Ebene zu bewe- 
gen, das zweite System ein kurzer Magnet, um welchen der Magnetpol 



Vierte Vorlesung. 309 

eine Centralbewegung macht. Nun erfahrt der Magnet eine Heine 
Drehung wodurch sich das Wirkungsgesetz der Centralbewegung iindert 
und ausserdem der Magnetpol einen kleinen Stoss. Das Gesagte soil 
gewissermassen ein Schema sein, in welchem die verschiedenen dem 
Principe der kleinsten Wirkung verwandten Principe zusammengestellt 
sind. Es zeigt sich, dass die Analogien mit dem zweiten Hauptsatze 
weder einfach mit dem Principe der kleinsten Wirkung, noch auch mit 
dem Hamilton'schen identisch sind, aber sowohl zum einen, wie auch zum 
andern in sehr naher Beziehung stehen. 

Ich habe zu Anfang betont, dass die Entwicklung der Wissenschaft 
nicht immer in stetiger Verfolgung der alten Wege vor sich geht, son- 
dern sehr hiiufig durch plotzliche Einfiihrung ganz neuer Methoden und 
Ideen gefordert wird. Wo konnte fiir letztere Art der Entwicklung ein 
fruchtbarer Boden sein als in Amerika, wo alles neu ist, wo die Geschick- 
lichkeit des Geistes, Ungewohnliches zu unternehmen, die grossten unvor- 
hergesehenen Schwierigkeiten zu besiegen stete Ubung findet, wiihrend wir 
in Europa wolgedrillt in den Bahnen der alten wis&enschaftlichen Me- 
thode uns zwar mit grosserer Leichtigkeit und Sicherheit bewegen, als 
die Bewohner der neuen Welt, aber dem Ungewohnten und Neuen gegen- 
iiber verbliifft und unbehiilflich sind. Sicher werden daher nicht bloss 
die Amerikaner aus ihren rastlosen Bestrebungen die Pflege der reinen 
Wissenschaft zu fordern den grossten Nutzen ziehen, sondern auch die 
Wissenschaft wird durch die Mitwirkung der Amerikaner stets mehr 
und grossartiger gefordert werden. Auch ich fiihle den hohen bildenden 
Wert, den es fiir mich hatte meinen engbegrenzten heimatlichen Hori- 
zont durch die Bekanntschaft mit der grossartigen Natur und Cultur 
Amerikas zu erweitern, wol das fruchtbringendste Experiment, das ich 
je angestellt habe. Ich sage Ihnen daher meinen besten Dank fiir die 
hohe Ehre, welche Sie mir durclj die Berufung zu diesen Vortragen 
erwiesen, und wiinsche nur, dass das von mir gebotene nicht ganz hinter 
der Grosse dieser Auszeichnung zuriickstehen moge. 




€^ 



a-^^>Ci>^^-x^ 



a 



uf 



COMPAEATIVE STUDY OF THE SENSORY AEEAS 
OF THE HUMAN CORTEX. 

By Santiago Ram(5n y Cajal. 

In order to respond worthily to the gracious invitation with which- 
Clark University has honored me, I ought to offer you, as was my original 
intention, a work of synthesis, a general summary of the present state of 
our knowledge of the minute anatomy of the nervous system. Unfortu- 
nately, the duties of my professorship, every day more pressing, have 
deprived me of the time necessary for the accomplishment of such a task, 
and have compelled me to moderate my ambition, and to limit it to 
presenting to you a modest analytical contribution to our knowledge 
of the microscopical structure of the sensory centres of the human cere- 
bral cortex, a subject to which I have devoted the leisure of the past 
months. 

This subject is so vast and so difficult that, in spite of my efforts and 
the time devoted to it, I have been able to clear up only a few points. 
Consequently, my contribution will be, to my utmost regret, a very 
incomplete one, treating, as it does, only the visual cortex as I have 
made it out in man and some of the higher mammals. I shall add, 
however, a few observations on the structure of other sensory regions. 

This anatomical study of the sensory areas of the cortex, at the 
present state of our knowledge, presents points of special interest, since, 
as you well know, neurologists who have interested themselves in the 
histology of the brain are divided at present into two camps, the unicists 
and the pluralists. 

The unicist doctrine, proclaimed by Meynert and reaffirmed quite 
recently by Golgi and KoUiker, supposes that all regions of the cortex 
possess essentially the same structure, functional diversity being due to 
diversity of origin of afferent or sensory nerves. This amounts to saying 
that cerebral specific energy of nerves is the necessary effect of the partic- 

311 



312 Santiago Ramon y Cajal : 

ular organization of each sense as well as of the special character of the 
stimuli received by the peripheral sensory surfaces, skin, retina, organ of 
Corti, etc. 

The pluralist doctrine, upheld recently by Flechsig, without rejecting 
the particular influence of connections with different nerves, maintains 
that diversities of function result also from the particular structure of 
each cortical area. 

It is this latter opinion, as we shall presently see, that presents a 
closer agreement with the observed facts. In fact, my researches tend to 
prove that the topographical specialization of the brain depends not only 
on the quality of the stimuli analyzed and gathered up by the sensory 
mechanisms, but also on the structural adaptations which the cor- 
responding cerebral areas undergo; since it is very natural to suppose, 
even if one were to form an a priori judgment, that the cortical areas con- 
nected with the spacial senses sight and touch, which form exact images 
of the exterior world with fixed relations of space and intensity, have by 
accommodation to the stimuli received an organization different from 
that existing in cortical areas attached to the chemical senses of taste or 
smell, and from that which is appropriate to the chronological sense 
hearing, which gives only relations of succession, free from every spacial 
quality. 

We may add that if there exist in the human cerebral cortex, as 
Flechsig supposes, besides the sensori-motor centres, other regions, asso- 
ciation centres, characterized by absence of direct sensory or motor con- 
nections, it seems very natural also to associate to these important 
regions of the brain, with which are connected the highest activities of 
psychic life, a special organization corresponding to their supremacy in 
the hierarchy of functions. 

But we must not carry to an extreme the structural plurality of the 
brain. In fact, our researches show that while there are very remarkable 
differences of organization in certain cortical areas, these points of differ- 
ence do not go so far as to make impossible the reduction of the cortical 
structure to a general plan. In reality, every convolution consists of two 
structural factors: one, which we may call a factor of a general order, 
since it is found over the whole cortex, is represented by the molecular 
layer and that of the small and large pyramids; the other, which we may 
call the special factor, particularly characteristic of the sensory areas, is 
represented by fibre plexuses formed by afferent nerve fibres and by the 



Visual Cortex. 313 

presence at the level of the so-called granular layer of certain cell types 
of peculiar form. 

But, before proceeding to outline the general conclusions of an ana- 
tomico-physiological order, that result from all our researches taken 
together, permit me to present very briefly the facts of observation. 

Visual Coktbx. 

The minute anatomy of the visual cortex (region of the calcarine 
fissure, sulcus cornu lobulus lingualis) has been already explored by sev- 
eral investigators, among whom we may make particular mention of Mey- 
nert, Vicq d'Azyr, Gennari, Krause, Hammarberg, Schlapp, KoUiker, et al. 
But their very incomplete researches have been performed by such insuffi- 
cient methods as staining with carmine, the Weigert-Pall method, or that 
of Nissl with basic anilines — methods which, as is well known, do not 
suffice at all to demonstrate the total morphology of the elements and the 
organization of the most delicate nerve plexuses. They led, however, in 
spite of the difficulties which stood in the way of these first analytical 
attempts, toward a precise differentiation of the visual cortex from other 
regions of the brain. At the outset two characteristic differences 
attracted the attention of the first investigators into the structure of the 
visual cortex : first, the existence of a very thick stratum of granules, sub- 
divided into accessory strata by laminas of molecular appearance; and, 
second, the presence in the intermediate layers of the cortex of a white 
lamina formed of meduUated fibres — which lamina may be seen with the 
unaided eye. This lamina, appearing in cross-section as a white line, has 
been named, in honor of the writers who first described it, the line of 
Gennari or Vicq d'Azyr. 

For the sake of brevity, we shall omit a detailed description and dis- 
cussion of the various layers admitted by the authorities on this region ; 
suffice it to mention in order the eight layers described by Meynert for 
the human cortex : First, molecular ; the second, layer of small pyram- 
idal cells ; third, layer of nuclei or granules ; fourth, layer of solitary 
cells ; fifth, layer of intermediate granules ; sixth, layer similar to the 
fourth, containing nuclei and scattered cells ; seventh, deep nuclear 
layer ; eighth, layer of fusiform cells. We may also mention the ar- 
rangement of layers recently described by Schlapp for the occipital 
cortex of the monkey : (1) layer of tangential fibres ; (2) layer of exter- 



314 



Santiago Ramon y Cajal, 




mffm 

m 






nal polymorphic cells ; (3) layer of pyram- 
idal cells ; (4) layer of granules ; (5) layer 
of small solitary cells ; (6) second layer of 
granules ; (7) layer poor in cells ; (8) layer 
of internal polymorphic cells. 

The investigations which I have made on 
the human cortex as well as on that of the 
dog and cat, by both the Nissl and Golgi 
methods, have led me to distinguish the fol- 
lowing layers : — 

1. Plexiform layer (called molecular 
layer by authors generally and cell-poor 
layer by Meynert). 

2. Layer of small pyramids. 

3. Layer of medium-sized pyramids. 

4. Layer of large stellate cells. 

5. Layer of small stellate cells (called 
layer of granules by the authors). 

6. Second plexiform layer, or layer of 
small pyramidal cells with arched axon. 

7. Layer of giant pyramidal cells (soli- 
tary cells of Meynert). 

8. Layer of medium sized pyramidal cells 
with arched ascending axon. 

9. Layer of fusiform and triangular cells 
(fusiform cell layer of Meynert). 

You see that we have modified current 
nomenclature by introducing terms which 
call to mind cellular morphology. For we 
believe that such trite expressions as "mo- 
lecular layer," "granular layer," must be 

Fig. 1. — Vertical section of tlie visual cortex ot man, 
calcarine sulcus, stained by Nissl's method — semischematic. 
1. Plexiform layer. 2. Layer of small pyramids. 3. Layer 
of medium-sized pyramids. 4. Layer of large stellate cells. 
5. Layer of small stellate cells. 6. Second plexiform layer, 
or layer of small pyramids with arched axon. 7. Layer of 
giant pyramids. 8. Layer of medium-sized pyramidal cells 
with ascending axon. 9. Layer of fusiform and triangular 
cells. 



Visual Cortex. 315 

banished once for all from scientific language, and they must be replaced 
by terms which point out dominant morphological characters in the 
nerve structures of each layer or some interesting peculiarity relative to 
the course and connections of the axis cylinder processes. The number of 
layers could be easily increased or diminished, because they are not sepa- 
rated by well-marked boundaries, particularly in Nissl's preparations. 
Thus the number of layers which I adopt is somewhat arbitrary. By 
distinguishing, however, nine layers, I have followed a criterion of indi- 
vidualization which seems to me the most convenient and suitable for my 
exposition of the cortex as a mechanism composed of elements at a cer- 
tain level which differ in special morphological features from those of 
neighboring levels. Besides, the number, extent, and size of cells in these 
layers vary a little in the different median occipital convolutions, as does 
also the degree of definite nidification, according as we study the convex 
or concave aspect of the gyri. Our description relates generally to the 
cortex of the margin of the calcarine fissure, the region where structural 
differentiation of the visual cortex is most pronounced. 

Plexiform Layer. 

The plexiform or molecular layer is one of the oldest cerebral forma- 
tions in the phylogenetic series. It presents characters similar to those 
of the human cortex in all vertebrates except the fishes. This has been 
fuUy demonstrated by the researches of comparative histology under- 
taken by Oyarzun (batrachia), by myself (batrachia, reptilia, and mam- 
malia), by my brother (batrachia, reptilia), by Eddinger (batrachia, 
reptilia, aves), by CI. Sala (aves). In the visual cortex of man, the 
structure of this layer coincides perfectly with that which my own re- 
searches, as well as those of G. Retzius, have revealed in the motor 
region. The only modification which may be noted, visible even by 
Nissl's method, is its notable thinness in the margins of the calcarine 
fissure (except in the sulci, and here it appears somewhat thinned). 
This diminution in thickness, noted by authors generally, depends 
probably on the small number of medium-sized and giant pyramidal cells 
in the underlying layers, because it is well known that each pyramidal 
cell is represented in the plexiform layer by a spray of dendrites. A 
similar opinion has been expressed by Bevan Lewis in order to explain 
irregularities in thickness of this layer in different regions of the cortex 



316 Santiago Ramon y Cajal: 

of the rabbit and guinea-pig. The structure of the plexiform layer is 
very complex. From my own researches, confirmed largely by those of 
Retzius, S chafer, KoUiker, and Bevan Lewis, it follows that it consists 
of an interweaving of the following elements: (a) the radial branches 
of the small, medium-sized, . and giant pyramidal cells, with which we 
must include in addition those of the so-called polymorphic cells ; (5) 
layer of terminal ramifications of the ascending axons of Martinotti ; 
(e) layer formed by the arborizations of the nerve fibres, terminal or 
collateral, which come from the white matter ; (cZ) layer of special or 
horizontal cells of the first layer (Cajal's cells, of Retzius) ; (e) layer of 
small and medium-sized stellate cells with short axons ; (/) layer of neu- 
roglia cells, well described by Martinotti, Retzius, and Andriesen. 

a. Terminal Arborizations of the Pyramidal Cells (Fig- 4). — As my 
observations have shown in case of the mammalian cortex, and those of 
Retzius for the human foetus, the radial trunk of the pyramidal cells 
does not end, as Golgi and Martinotti supposed, in a point entwined by 
neuroglia elements in connection with the blood-vessels, but in a spray of 
varicose dendrites covered with contact granules, spreading out some- 
times over a considerable area of the plexiform layer. In my first work 
on the cerebral cortex, I thought that the only cells whose terminal 
dendrites reached up to the first layer were the medium-sized, small, 
and giant pyramidal cells ; but my latest researches have enabled me 
to discover that all cells possessing a radial stem, without exception, 
including even those of the deeper layers, are represented in the plexi- 
form layer by a terminal dendritic arborization. It is without doubt 
an important structural law whose physiological import must be very 
considerable. We may observe that large trunks which arise from the 
giant pyramids divide into a spray with very long and thick branches 
having their distribution in the deeper level, while the slender stems 
emanating from the medium and small sized pyramids form an arboriza- 
tion of numerous slender branches of limited extension and distributed 
particularly through the superficial laminte of the plexiform layer. This 
distribution, which is not absolutely constant, leads us to surmise that 
the terminal arborizations of each kind of pyramidal cell come into contact 
with special neuritic terminal arborizations in traversing this first layer. 

The trunk and end brush intended for the first layer appear not only 
in preparations made by the chromate of silver method ; for I have 
stained them perfectly with methylene blue (method of Ehrlich-Bethe) 



Visual Cortex. 317 

in case of young animals, and also in adult gyrencephalous mammals, 
such as the dog and cat. Besides, in good preparations by Ehrlich's 
method, particularly when fixation has been made a short time after the 
impregnation, one may see very distinctly the contact granules of the 
dendrites, processes which I was first to describe and whose existence 
has been confirmed by many investigators since. With methylene blue 
they present the same appearance as in Golgi preparations, i.e. they are 
slender and short, stand out at a right angle, are sometimes divided, and 
end freely in a rounded knob. This proves, accordingly, how groundless 
are all the gratuitous objections which have been brought against the 
preexistence of these appendages, as well as against their mode of termi- 
nation. Among the entirely arbitrary conjectures which have been made 
as to the disposition of these appendages we include also W. Hill's opinion, 
who considers them the fibres of a reticulum that is incompletely stained 
by means of the chromate of silver. We must proclaim emphatically 
that at present there is no method of staining cellular processes that 
is capable of disproving the agreeing results of the methods of Golgi, 
Ehrlich, and Cox. Whoever, having as a foundation the revelations of 
any one of these methods, has considered it possible to demonstrate the 
existence of such a reticulum has only exposed to view his own lack of 
experience in handling these important means of analysis. 

b. Special or Horizontal Cells of the Plexiform Layer. — These interest- 
ing elements, which I discovered in the cortices of the small mammals (rat, 
rabbit, guinea-pig), have been successfully investigated by Retzius in 
case of man, as well as by my brother in batrachians and reptiles, and by 
Veratti in the rabbit's embryo. They present in the visual cortex, where 
I have stained them very often, the same characters as in other regions 
of the brain. As I have already described these elements elsewhere, I 
shall give here only an outline, to which I may add a few remarks derived 
from my recent observations upon man (Fig. 2). 

Following the example of Retzius, when we study the horizontal cells 
by Golgi's method in a human foetus from the seventh to the ninth 
month, or in case of a newborn babe, we notice that they are distributed 
throughout the entire thickness of the plexiform layer, but are especially 
numerous in close proximity to the pia. Their form is very variable, 
sometimes fusiform or triangular, and again stellate, with the angles 
extending out into the long processes. But the characteristic feature of 
these elements is due to the fact that their processes, which are variable 



318 



Santiago Ramon y Cajal. 




Visual Cortex. 319 

in number and very large at their origin, give rise, after a few divisions, 
to an extraordinary number of varicose horizontal fibres, extremely long, 
from which spring at right angles numberless ascending secondary 
branches terminating in rounded knobs near the cerebral surface. Very 
often the superior surface of the cell body also gives rise to some of these 
ascending branches, which sometimes have a considerable thickness. 

In what way do these tangential fibres terminate ? Is it possible to 
discern among them certain processes possessing the characters of axons ? 

Upon careful examination of the best preparations obtained from 
cortices of human embryos, we discover easily that these processes, 
when they become very fine, have all the appearances peculiar to axons. 
There is no morphological distinction which would enable us to distin- 
guish the two classes or species of cellular processes. That which most 
strikes one is the enormous length of their horizontal fibres (tangential 
fibres of Retzius). One can follow them for two or three tenths of a 
millimeter without being able to discover their true termination. How- 
ever, in certain cases it is possible to demonstrate that the tangential 
fibres, after having given rise to a great number of vertical twigs, become 
thinner and finer, and finally subdivide into terminal branchlets, which 
spread out under the pia or in the superficial laminse of the first layer. 

On comparing these cells of the human brain with their homologues 
in the higher mammals (rabbit, cat, etc.), we discover that among the 
latter they give rise to a relatively small number of tangential branches, 
and that these extend a much shorter distance. This is the reason we 
consider the remarkable profusion and the extreme length of the hori- 
zontal fibres as one of the most characteristic features of the human 
cortex. 

Retzius did not succeed in staining the horizontal cells in man except 
in the foetal period. Accordingly, it was impossible to know what be- 
comes of these elements in the adult, and whether, as Retzius is inclined 
to think, all the processes that we find in the embryonic period persist. 
My recent researches on the cortex of infants fifteen months and even 
fifteen and twenty days old, in which I have been successful in staining 
the horizontal cells, suffice to furnish a few data which, if they do not 
solve the problem once for all, at any rate place the question in a some- 
what more favorable light. 

When we examine the plexiform layer of a babe fifteen days old, 
we find considerable changes in the horizontal cells. First of all, we 



320 Santiago Ramon y Cajal: 

notice that they have become smaller, and that the tangential processes 
have duninished in diameter while they have become notably lengthened. 
But the peculiarity which most strikes the attention is the almost total 
disappearance of the ascending collateral branches. This atrophy begins 
in a progressive thinning of the processes and in the reabsorption of their 
terminal varicosities ; then the whole branch disappears, so that the only 
structures left are the horizontal fibres, whose ensemble forms throughout 
the thickness of the plexiform layer a system of parallel fibres of enor- 
mous length. There are places, however, where the ascending branches 
persist, but very much changed as to their direction, having become 
oblique instead of vertical, becoming branched several times, and termi- 
nating in the plexiform layer without reaching so far up toward the 
pia as before. In a word, most of the vertical branches seem to me to 
represent an embryonic arrangement corresponding to the interstices, for 
the most part vertical, between the epithelial cells of the cerebral cortex 
of the foetus, which proves once more, as I have demonstrated in other 
nerve centres, that during the period of evolution the neuron is the locus 
of a double series of functions : on the one side a vegetative building up 
of the dendrites ; on the other, reabsorptions and transformations of the 
cells which persist. 

Have the horizontal cells with which we are now concerned a true 
functional process ? In case this is so, what is the part played by these 
elements in the vast system of nervous relations established in the plexi- 
form layer ? 

In preparations of the human brain stained with chromate of silver, it 
must be confessed, it is not easy to solve this important question, since 
the purely morphological criterion, which is sufficient to distinguish the 
axon in other neurons, cannot be applied to horizontal cells, all the pro- 
cesses of which, on becoming finer, have the form of true axons. Thus, 
in spite of Veratti's affirmation, we believe that this method will shed no 
light upon the subject, even when applied to embryos. In order to ap- 
proximate to any solution of the problem, we must use a method capable 
of staining nerve prolongations in a manner to differentiate them from 
dendrites. It was only after using Ehrlich's methylene-blue method upon 
the motor and visual cortex of the cat that I became convinced that the 
horizontal cells have in reality a very long axon, which is provided with a 
medullary sheath. The other processes, which we have called horizontal 
fibres, represent true dendrites, as is shown by two peculiarities: the great 



Visual Cortex. 321 

facility with whicli they take methylene blue, and their pronounced vari- 
cosity after fixation with ammonium molybdate. We must repeat that 
this varicose alteration, which is a striking modification in the form of 
cellular prolongations, presents itself only in dendrites. The neurites 
maintain perfectly, with methylene blue, their normal contours, unless 
exposure to the air, necessary to obtain the selective staining, has been 
too long. 

As to the axon, it may be sufficiently well demonstrated in horizontal 
sections of the plexiform layer in the form of a pale blue fibre, except the 
initial portion and the nodes, which present a dark blue staining. This 
is a property of all parts of a fibre not surrounded with a medullary 
sheath. At the point of certain constrictions we may succeed in dis- 
covering a few collaterals springing out at right angles, provided also 
with myeline sheaths. Finally, one is sometimes so fortunate as to dis- 
cover in an axon of this kind true bifurcations situated at a great dis- 
tance from the cell of origin, but always in the plane of the plexiform 
layer. Unfortunately, the methylene blue does not stain the terminal 
nerve arborizations. This has prevented me from learning in just what 
way these axons terminate and with what axons they are dynamically 
associated. It is possible that certain heavy horizontal fibres come into 
contact with the horizontal cells, since they never bend downward 
toward the underlying layers, as do the medium-sized and finest medul- 
lated fibres. They belong probably to the terminal arborizations of 
Martinotti's ascending axons and, perhaps, also to the collaterals and 
terminals coming in from the white matter. 

e. Cells with a Short Axon (Fig. 3, G-,I1,F}. — A few years ago, while 
studying the cerebral cortex of the small mammals, I discovered, besides 
the gigantic horizontal cells, other elements which I called polygonal cells. 
These are characterized by their stellate form and by their short axon, 
which ramifies and ends within the limits of the plexiform layer. These 
cells, whose existence neither Schafer nor Lewis seem to have been able to 
confirm, — no doubt on account of the insufficiency of their attempts to 
obtain an impregnation of them, — are much more abundant than might 
have been supposed from my first observations. However, I must acknowl- 
edge that, they are not at all easily impregnated with chromate of silver 
and that, in order to find a sufficient number for study, we must make a 
great many attempts at staining them. On the other hand, Ehrlich's 
method stains them very readily in the dog and rabbit. In these animals 



322 



Santiago Ramon y Cajal: 



— and I think that it holds true also in man — the plexif orm layer of the 
cerebrum is as richly supplied with elements with a short axon as the 
molecular layer of the cerebellar cortex. They occur in all levels of the 
layer and differ remarkably in size and shape. The majority of them 
are stellate and are comparable in size to other cells with short axons 




Fig. 3. — Cells and neuritlc terminal arborizations in the 1st and 2d layers ; visual cortex of 
infant 20 days old. A and B, neiu-itic plexus, extremely fine and dense, situated in the layer of 
small pyramids ; C, an analogous arborization, but not so dense ; O, a small cell whose ascending 
axon forms a similar arborization; £, spider-shaped stellate cell of the 1st layer; F, G, cells with 
short axon branching loosely in the plexiform layer ; a, axon. 

that occur in the deeper layers of the cortex. Others are smaller, 
resembling in their minuteness the granules of the cerebellum. But 
whether large or small, the morphological characters of these elements 
are very similar. Their dendrites are divergent, extremely branched, 
and distributed exclusively to the plexiform layer. Their neurites are 



Visual Cortex. 323 

usually very short, subdivide in a most complicated manner in the neigh- 
borhood of the cell, but never cross the deep boundary of the first layer. 

From the point of view of the direction and length of their neurites 
aU these elements may be classified into three varieties : (1) Stellar cells 
with horizontal neurite which becomes resolved after a varying distance, 
generally very long, into a terminal arborization which has the appear- 
ance of being connected with the terminal branches of the remote pyra- 
mids. (2) Cells of generally smaller size whose neurite branches either 
laterally or vertically from the cell body, but always at a moderate dis- 
tance (Fig. 3, Gr, jF). (3) Very small cells (which I discovered recently 
in the human cerebral cortex) provided with numerous fine, divergent, 
and slightly branched dendrites, whose neurite, extremely slender, breaks 
up near its origin into a dense arborization, exceedingly fine and compli- 
cated. We shall designate these elements dwarf or spider-shaped cells. 
They may be found, as we shall see, in all the layers of the cortex 
(Fig 3, ^). 

To sum up : bearing in mind the form of cell bodies and formation 
and connection of axons, all the stellate cells of the plexiform layer, 
including the horizontal or special cells, seem to me similar to the stellate 
cells of the molecular layer of the cerebellum and to those which occur 
in the layers of the same name in the cornu ammonis and fascia dentata. 
Their function is probably to establish connections between terminal 
arborizations as yet imperfectly made out, possibly those formed by the 
ascending axons of Martinotti, or the association fibres coming up from 
the white matter with the terminal branches of the pyramidal cells. 
The function of the great horizontal cells would seem to be to establish 
connections between elements, that is to say between terminal neuritic 
arborizations and radial dendrites, separated by very considerable dis- 
tances ; while the medium-sized and small elements, with their short 
axons, would perform the same associative function at short or moderate 
distances. 

d. Martinotti's Ascending Fibres. — There is no lack of these in the 
visual cortex, although it has seemed to me that they are not so numerous 
as in other regions of the brain. Their terminal ramifications, well known 
from the researches of Martinotti as well as my own, occupy really the 
whole plexiform layer, where they extend over wide areas, distributing 
themselves preferably into its deeper levels and coming in contact with 
cells with short axons and, possibly, also with the large horizontal cells. 



324 Santiago Ramon y Cajal: 

Granting that the cells of origin for these fibres lie in layers of the cortex 
that contain sensory fibres, we might suppose that Martinotti's ascending 
axons represent intermediate links placed vertically between these sen- 
sory fibres and cells with short axon in the plexiform layer. And as 
these are connected, perhaps, with the dendrites of the pyramidal cells, 
the result would be that the sensory stimuli, entering the cortex in this 
indirect way, would be compelled to traverse two intercalated nerve 
cells before reaching the pyramids. 

e. Neuroglia Cells. — These conform in the visual cortex to the well- 
known types of other cerebral regions. We find accordinglj^ : (1) Cells 
with long radii, the marginal cells well described by Martinotti, which 
lie just under the pia. They emit long, smooth, descending processes 
radiating across the plexiform layer, ending at different levels both of 
this and of the layer of small pyramids ; (2) Cells with short radii. 
These elements, long since described by Golgi, and described in de- 
tail by Retzius, by myself, Andriesen, KoUiker, and others, are charac- 
terized by their form, very often stellate or fusiform, by their location in 
all levels of the plexiform layer, and by the great number of their pro- 
cesses, short, spongy, branching, and bristling with innumerable contact 
granules, which penetrate into the spaces lying between the neuro-proto- 
plasmic plexus and are well spread over the interstices of the elements 
which must not come into contact. It is in virtue of this intricate rela- 
tion between these appendages and the cell bodies and dendrites, as well 
as for other reasons which we have not time to dilate upon here, that we 
attribute to the neuroglia elements with short processes an insulating 
role. According to my view, they prevent inopportune contacts, while 
their processes exercise due regard to all points of cells or fibres where 
contacts exist and nerve currents pass. 

Layer of Small Ptbamids. 

This layer is well separated from the 1st, but blends by insensible 
gradations with the 3rd, or layer of medium-sized pyramidal cells (Fig. 
4, 5). 

Examined in Nissl preparations this layer presents a great number of 
small pyramids, very poor in chromatic granules and separated by a 
plexus of fibrils much more dense than in the case of cells of the deeper 
layers. We find also, scattered irregularly, stellate or triangular cells 



Visual Cortex. 



325 



larger than the pyramids. These are the giant cells with short axon, as 
is shown in good chromate of silver preparations (Fig. 5, D, C). We 
shall now discuss the cells of this layer, beginning with the pyramids. 
Pyramids. — The morphology and relations of these cells being well 




Fig. i. — Small and medium-sized cells of the visual cortex of an infant 20 days old (calcarine 
sulcus). A, Plexiform layer ; B, layer of small pyramids ; C, layer of medium-sized pyramids; a, 
descending axon ; b, recurrent collateral ; c, dendritic trunk of giant pyramid. 

known since the researches of Golgi, Retzius, and myself, I shall limit 
my remarks to a bare mention of a few peculiarities of their disposition 
in the visual cortex. 

It will be noticed that these cells are generally smaller and more 



326 Santiago Ramon y Cajal: 

numerous in the visual centres than in other cortical areas. Sometimes 
the more superficial cells are arranged in one or two regular files and 
separated from those beneath by a fine dense plexus of fibres. 

The small pyramids give rise to the following processes : an axial 
dendrite, often bifurcated near its origin, which runs to the plexiform 
layer and terminates in a spray of fine branches, which often ascend 
to the neighborhood of the pia; basilar divergent dendrites, rather 
long and repeatedly branched; and, finally, a fiiae descending axon, 
which, in most favorable specimens, can be followed down to the neigh- 
borhood of the white matter. From the initial portion of its course spring 
three, four, or a larger number of collateral processes, which traverse, 
with many subdivisions, in a horizontal or oblique direction, a very con- 
siderable extent of the second layer. From the small pjTamids lying 
close to the plexiform layer, and even from some cells more deeply situ- 
ated, the first two collaterals recurve, ascending sometimes, as Schafer 
has discovered, up to their termination in the first layer. However, this 
termination in the first layer is much less frequent than might be 
inferred from this authority's descriptions and drawings. In our prepa- 
rations of the visual and motor cortex of a child a few days old and of a 
cat twenty-five days old, the great majority of the recurrent collaterals do 
not cross the boundary of the second layer. Here, in conjunction with 
many neurites belonging to cells with short axons, they assist in forming 
a very dense plexus, which contains in its meshes the primary dendrites 
of the small pyramids. Generally, — and this may be considered as an 
answer to the authorities who strive to convert the recurrent course of 
the collaterals into an argument for the doctrine of the cellulipetal con- 
duction of these fibres (v. Lenhossek, Schafer), — I may affirm that the 
vast majority of the initial neuritic collaterals • — and I consider such all 
those that arise within the gray matter — always come into contact with 
some of the dendrites belonging to homologous nerve cells situated at dif- 
ferent levels of the same cortical formation. When the cells to which 
they correspond lie in the same or a deeper plane, the collaterals intended 
for them take a horizontal, descending, or oblique course ; but if the cells 
of the same category are situated in a more superficial plane than the 
point of origin of the collateral, they must describe a recurrent arc in 
order to reach their destination. 



Visual Cortex. 327 

Layer op Medium-sized Pyramids. 

Being a continuation by insensible gradations of the small pyramidal 
layer, it contains cells of precisely similar form, differing from the cells 
of the second layer only in their somewhat greater size, their longer 
radial dendrite, and, ordinarily, by a larger number of neuritic collaterals 
(Fig. 4, C). In the deeper level of this layer may be observed — very 
seldom, however — large pyramidal cells, but not so large as those situ- 
ated in the seventh layer. 

Cells with Short Axon of the Second and Third Layers. — These 
elements, almost as numerous as the pyramidal cells themselves, may be 
seen scattered irregularly throughout the entire thickness of the two 
layers. They are generally more numerous near the limits of these 
layers, that is to say, in the superficial portion of the second and in the 
deeper level of the third layer. 

Although in form and size these elements are very variable, and 
although there are transitional forms which make it often difficult to dis- 
tinguish between them and to subdivide them into well-pronounced types, 
still, by considering the size of the cell body and the character of the 
axon, they may be divided into the following five classes : (a) ceUs with 
short ascending axon ; (5) cells with short descending axon ; (c) cells 
with horizontal or oblique axon ; (c?) dwarf or spider-shaped elements ; 
(e) fusiform or bipanicled cells, whose axon breaks up into a fibrillar 
arborization. 

a. Cells with Ascending Axon (Fig. 5, a, B'). — As may be seen in 
Fig. 5, these cells belong to two principal varieties : (a) Gigantic cells, 
with long dendrites (Fig. 5, A, C). These are quite numerous in the 
visual cortex, where they occupy preferably the deep portion of the third 
layer. Their form is stellate, sometimes fusiform or triangular. From 
their angles arise several varicose, thick, and very long dendrites, often 
disposed as two brushes, the one ascending, the other descending. The 
axon takes its origin either from the cell body or from a dendrite. 
Sometimes it describes an arc, whose concavity is toward the surface, on 
its way outward to become resolved into an arborization of very few 
branches. The characteristic feature of this arborization is the enormous 
length and the horizontal or oblique direction of its terminal twigs. 
These traverse a very considerable portion of the second and third 
laj^ers, where they make contact with numberless pyramidal cells. It 




Fig. 5. — Large stellate cells having short ascending axons, 2d and 3d layers, visual 
cortex, infant 15 days old. A, elements of the 3d layer with axons divided into long horizontal 
branches ; B, small cell with arched axon from the layer of small pyramids ; C, large cell with 
arched axon; D, large cell from the boundary of the 1st layer; F, cell with arched ascending 
axon branching in a most complicated manner; a, a, a, axons. 



Visual Cortex. 329 

may be added that these gigantic cells may be recognized even in Nissl 
preparations by their stellate form and considerable size. They corre- 
spond, probably, to the globular cells of Bevan Lewis and other writers. 
(by Medium-sized type : This is a fusiform or stellate cell, whose size 
does not exceed that of the small or medium-sized pyramids. It is 
characterized above all by its axon, which is slender and ascending, and 
which terminates in a complicated arborization with many varicose 
branches and with relatively small spread at varying levels of the second 
and third layers. As to the dendrites, they appear varicose and diverge 
in all directions, but usually do not extend to the first layer (Fig. 5, F, 
and Fig. 3, i)). 

i. Cells with Descending Axons. — These are stellate, triangular, or fusi- 
form, of medium size, and provided with many ascending and descending 
dendrites. They occur chiefly, as has been pointed out by Schafer for 
other regions of the cortex, along the superficial boundary of the layer of 
small pyramids (Fig. 5, B, and 6, C). Their axons descend through 
the second and sometimes through the third layer, giving off to them 
a few collaterals, and terminate in a diffuse arborization throughout the 
different levels of these layers. Very frequently this axon, after descend- 
ing a certain distance, emitting a few collaterals to the layer of small or 
medium-sized pyramids, traces an arc with concavity toward the surface 
and ascends to terminate in an arborization, very complicated and with 
exceedingly varicose branches, in the layer of small pyramids close to the 
plexiform layer (Fig. 5, B). As seen in Fig. 6, which reproduces certain 
cells of short axons from the visual cortex of the cat, these elements with 
descending axons are very numerous in other gyrencephalous mammals. 
We also find a variety of cell, recognized in man, pyriform, uni-polar, 
whose single descending process gives rise to a bouquet of varicose 
dendrites and an axon (Fig. 6, a, 5). The collaterals and terminal 
arborizations of these axons form in the cat a dense plexus throughout the 
superficial plane of the layer of small pyramids. 

The great number of cells with short axons which occur in the most 
superficial lamina of the layer of small pyramids has induced certain writ- 
ers, such as Schafer and Schlapp, to consider this transitional region as a 
special layer, which they call the layer of superficial polymorphic cells. 
We cannot subscribe to this innovation because, in spite of the great 
number of these cells, this transitional lamina contains also a large num- 
ber of small pyramids, that is to say, cells which, in addition to their 



330 



Santiago Ramon y Cajal . 



morphological varieties, have the same connections as ordinary pyramidal 
cells. Of course, if for the subdivision of the cortex into layers we take 




Fig. 6. — Cells with short axons from the layer of small pyramids, visual cortex of cat aged 
28 days, a, b, small pyriform cells with short descending axons ; c, cell with arched axon ; e, /, 
cells with descending axons distributed to the medium-sized pyramids of 3d layer. 

as our basis of classification the form of cell bodies, independently of other 
characters, we might be entitled to differentiate between the first and 
second layer consisting chiefly of stellate cells ; because in this region, as 



Visual Cortex. 331 

is well known, the small pyramids have a stellate or triangular form. 
But, in assigning to an element a place in his classification, one must' not 
decide from the form alone, which in case of superficially placed pyramids 
is a function of their position. In fact, we find that the form of these 
cells varies according to their proximity to the plexiform layer. The 
true characteristic of a pyramidal cell consists in the presence of a long 
axon extending down to the white matter and of a spray of dendrites 
(supported or not by an intermediate trunk) spreading up into the plexi- 
form layer. Now, in the light of such a criterion, it is easy to see that 
sufficient reason does not exist for making out of the most superficial 
pyramids a distinct category of cells to be used as a basis for the creation 
of a new cortical layer. 

c. Cells with Horizontal or Oblique Axon (Fig. 7). — These elements, 
which are angular or fusiform, with their long axes more or less hori- 
zontal, possess few, but rather long, dendrites. Their axon arises gen- 
erally from the lateral aspect of the cell body or from a thick polar 
dendrite, takes from the first a horizontal or oblique direction and, after 
giving oJf a few collaterals, terminates, sometimes after extending to a 
considerable distance, in an arborization widely spread but with few 
branches. In certain cells of this category, it is shorter and subdivides 
in the immediate neighborhood of the cell body (Fig. 7, U, (7) . 

d. Dwarf or Spider-shaped Cells. — Brought to our attention by CI. 
Sala in the corpus striatum of birds, mentioned also by my brother in 
the cerebral cortex of batrachians and reptiles, these strange elements are 
notably abundant and of very pronounced character in the cerebral cortex 
of man and gyrencephalous mammals. They are found irregularly scat- 
tered in all layers of the visual area. Their soma is very small, not ex- 
ceeding the diameter of the nucleus by more than five or six fi. About 
the nucleus is a thin lamina of protoplasm which is drawn out into 
a great number of dendrites, delicately varicose, radiating, slightly 
branched and short. The appearance of these dendrites is such that one 
might mistake the cell, at first sight, for a neuroglia corpuscle with short 
processes. But, examining them with a high power, we recognize at 
once that their slender dendrites do not possess collateral appendages 
(contact granules), so characteristic of processes of neuroglia cells. Finally, 
attentive examination reveals the axon, a delicate fibre, which becomes 
resolved immediately into a very dense varicose arborization of incompar- 
able fineness. Often this terminal plexus is so extremely fine that it 



332 Santiago Ramon y Cajal: 

appears through an ordinary objective as a yellowish or brownish spot in 
the neighborhood of the cell and resembling somewhat a granular precipi- 




FiG. 7. — Cells with short horizontal or oblique axons situated in the 2d and 3d layers, visual 
cortex of infant a few days old. A, B, cells with axons almost horizontal from 2d layer; C, D, E, 
cells with short axon diffusely branched; JP, S, I, pyriform cells of the 1st layer, whose sig- 
nificance is still uncertain; G, small cell with very short axon diffusely branching within the 
1st layer. 

tate. In some cases this arborization is coarser and can be seen with a 
Zeiss objective D or E. At the level of the superior boundary of the 
layer of small pyramids, in the visual cortex of the child and even of 



Visual Cortex. 333 

other mammals, may often be seen a dense plexus of exceedingly slender 
branching fibrils. Their original fibre appears to come from the deeper 
levels of the 2d layer (Fig. 3, A, B, C). These terminal plexuses often 
take the impregnation irregularly, which gives the appearance of brownish 
or coffee-colored spots scattered and sometimes arranged in a row just 
underneath the plexiform layer. At first I was not successful in tracking 
satisfactorily the fibres of origin and, therefore, hesitated as to stating 
the significance of these interesting arborizations. Very recently, how- 
ever, in two or three fortunate specimens I have been able to demonstrate 
the connection between this plexus and the fine ascending axons of certain 
small cells situated in the deeper level of the 2d or outer level of the 3d 
layer. I am, therefore, now inclined to consider this intermediate, or sub- 
plexiform, nerve plexus as consisting of terminal arborizations intended 
for the small pyramids. The fibres of origin spring from more deeply situ- 
ated spider-shaped cells very hard to impregnate. I may add that these 
plexuses are not lacking in the cat and dog, although in these animals 
the fibrillse are not so numerous nor so extremely fine as in the human 
brain. Permit me also to add that they occur in all regions of the cor- 
tex, although up to the present we have obtained the best impregnation 
of them in the visual area. 

e. Small Bipanioled Cells. — In the visual region, as well as in other 
areas, of the human cortex we find in profusion certain small cells vertically 
elongated. Their axon presents the very singular feature of breaking up 
into long slender brushes of terminal fibrillse. At first, I thought that 
these singular cells were forms characteristic of the acoustic area, for here 
they are remarkably developed and very numerous. Further investiga- 
tion, however, has convinced me that they occur in all parts of the 
cortex, disposed in greatest numbers along the lower level of the 2d and 
3d layers (Fig. 8 and Fig. 11, I], F}. 

As stated above, we are discussing the small spindle-shaped cells 
with poles radially disposed, which give rise to groups of dendrites, 
slender, unprovided with contact granules, very finely varicose, and often 
arranged in long ascending and descending brushes. In some cases these 
are so fine that on superficial examination they might be mistaken for 
delicate neuritic arborizations. But the most striking peculiarity of 
• these cells concerns the subdivisions and course of their axons. This pro- 
cess is very delicate. It ascends or descends a certain distance, then gen- 
erally gives off a few collaterals at right angles which soon subdivide into 



334 



Santiago Ramon y Cajal: 




Fig. 8. — Small fusiform, bipanicled cells 
from auditory cortex of infant (1st temporal 
convolution). A, cell giving origin to a de- 
scending axon moderately branched; B, cell 
whose axon breaks up into a number of pen- 
cils of very long ascending and descending 
fibrils ; a, axon. (Examined with Zeiss apo- 
chromatic obj. 1.30.) 



ascending or descending fibrillse, and 
finally it breaks up into brushes of 
very slender filaments which run radi- 
ally, extending throughout almost the 
entire thickness of the cortex. As a 
whole this arborization with its initial 
collaterals forms one or several parallel 
brushes, the fibrils of which skirt the 
trunks of the pyramids and adapt them- 
selves to the cell bodies, over which 
they appear to creep, like the creeping 
fibres of the cerebellum on the branches 
and bodies of the Purkinje cells. 

In the brain of the human infant 
at birth these arborizations have not 
attained complete development and 
present but few vertical branchlets. 
It is not until twenty or thirty days 
after birth that we can observe the 
long and complicated terminal brushes. 
In certain areas, the acoustic, for ex- 
ample, each neurite may form as 
many as five ascending or descending 
brushes. The fibrils of which they 
consist are so delicate that in order 
to see them well we must use the 
highest apochromatic objectives. 

If now we consider all the differ- 
ent kinds of cells having short axons, 
of Avhich we have given a somewhat 
fastidious description, from the point 
of view of their connections and their 
probable functions, we may character- 
ize them as special cells of association. 
The form of their cell body and the dis- 
position of the axon vary according to 
the number, form, and position of the 
cells to which they must convey nerve 



Visual Cortex. 335 

stimuli. Thus cells with a horizontal axon must be intended to transmit 
impulses to elements, probably pyramidal cells, which occur at the same 
level in the cortex. Those whose axon is vertical, ascending or descend- 
ing, would naturally transmit impulses to elements of different layers. 
Those which are bipanieled would serve to associate dynamically a great 
number of pyramids in vertical series. Finally, the small, spider-shaped 
cells may have for their function association of groups of pyramids very 
close together. Unfortunately for this theory, we do not know from which 
nerve fibres all these elements of association receive their initial stimuli. 
Accordingly, we must be resigned to remain in ignorance as to the path of 
the afferent impulses and, as well, in regard to the special influence which 
these elements must exercise. It seems very probable, however, that 
their function consists not only in facilitating the spread of incoming 
stimuli, but also in adding to it something new, some specific modifica- 
tion which cannot now be determined. We shall return to this point in 
our general conclusions upon this work. But we may see from the above 
how many paths nature has opened up to render association of nerve 
impulses possible in every direction and through any distance. That 
which proves the importance of these association cells and leads us to 
surmise that they play an important psychic role is the fact that they are 
extremely numerous in the human brain. They are found in the animal 
brain as well, but are not numerous and are usually confined to the 
boundary of the 1st layer. 

I conclude here my exposition of the prosy topics that I chose as 
the theme of this lecture. And nothing remains except to thank you for 
the attention and good will which you have shown me in spite of the 
extreme dryness of the subject-matter. 



LECTURE II. 

Layer of the Large Stellate Cells. 

Mt recent researches in the visual cortex of man have led to the unex- 
pected discovery of certain large cells of stellate form possessing an axon 
which descends to the white matter. Figs. 9 and 10 represent very 
clearly the most common forms of these strange elements. They are 
differentiated immediately from pyramidal cells by their lack of a radial 
trunk. Generally speaking, the cell body is stellate, but there is no lack 
of semilunar, triangular, and even mitral forms. Their dendrites are 
thick and much branched, and extend in all directions, especially horizon- 
tally, without ever leaving the territory of the 4th layer. In man these 
processes are sparsely provided with contact granules, while they are very 
numerous in the homologous cells of the mammalia (cat and dog). 

As to the axon, it is rather large, arises from the inferior surface of the 
cell body, descends through the 4th layer, sometimes tracing here accom- 
modation curves, and after crossing the 5th, 6th, 7th and 8th layer, passes 
into the white matter and is there continued as a meduUated nerve fibre. 
In passing through the 4th and 5th layers it gives off three, four, or a 
larger number of, often, very large collaterals which end in arborizations 
extending over a considerable area in these layers. It is not uncommon 
to see these collaterals taking a recurrent course to become distributed in 
planes above the point of origin ; but in this they never trespass on the 
boundaries of the 4th and 5th layers. Finally, and this is a very frequent 
disposition in the adult cortex, this axon, after having given off its col- 
laterals, becomes notably finer. Taking into consideration its diameter, 
sometimes less than that of its first collateral, we might be led to mistake 
it for the latter rather than a true continuation of the axon. We shall 
return to this peculiarity, which is presented by many cells in the visual 
cortex. The stellate cells present a similar character in the adult human 
cortex, and I reproduce in Fig. 10 their principal types impregnated (long 
method of Golgi) in the case of a man thirty years old. The only 

336 



Visual Cortex. 



337 



difference that we remark between these cells in the adult and infant 
brain is the greater development of the dendrites, which extend long 
distances in horizontal planes in the adult. The volume of the soma also 




Fig. 9. — Layers i and 5, with portion of 6 ; stellate cells of the visual cortex, infant 20 days 
old, calcarine sulcus. A, layer of large stellate cells ; a, semilunar corpuscle ; b, fusiform horizontal 
cell ; c, cell with radial trunk ; e, cell with arched axon ; B, layer of small stellate cells ; /, horizon- 
tal fusiform cells ; g, triangular cells with heavy arching collaterals ; C, layer of small pyramids 
with arched axon ; h, cells of this type. 

increases with age, which shows that growth of dendrites does not depend 
solely on the lengthening out of the initial or primitive protoplasm of the 
cell, but also on an actual augmentation of cell substance. 



338 



Santiago Ramon y Cajal : 



Cells with Short Axon. — As it happens in other cortical layers, the 
4th contains a large number of cells with short axon. The following 
three types may be distinguished : — 




Fig. 10. — Large stellate cells of the adult brain, man 30 years old, neighborhood of calcarine 
sulcus. A, B, C, F, stellate cells of the 4th layer ; D, E, K, medium-sized stellate cells of 5th 
layer ; G, S, J, cells with short axon. (Golgi's slow method.) 

(a) Cells, stellate, fusiform, or triangular, whose axon ascends to be 
distributed in the superficial plane of the 4th layer (Fig. 11, A, C, 2)). 

(J) Cells of similar form and position, but whose axon distributes 
itself to the layer of medium-sized pyramids (Fig. 11, B'). 

(c) Spider-shaped cells with a notably short axon, as may be seen 
in Fig. 13, U. 




Fig. 11. — Cells of the visual cortex, infant 15 days old, 4th layer. A, cell sending axon to 
superior portion of 4th layer ; B, cell whose axon branches to the 3d and 4th layers : C, another cell 
sending branches into the 3d, 4th, and 5th layers ; E, F, very small bipanicled cells from layer of 
medium-sized pyramids; a, axon. 



340 



Santiago Ramon y Cajal. 



The cells with ascending axon are remarkable on account of the curi- 
ous arched course of the latter. It has in some cases initial collaterals. 

The stellate cells as well as other cells with the short axon are also 
found in the cortex of the cat and dog, where they form a well-defined 
layer of their own, corresponding, considering the character of its elements, 
to the 4th, 5th, and 6th in the visual cortex of the child, Fig. 12. Cells 




Fig. 12. — Stellate cells from visual cortex of a cat aged 28 days. A, layer of stellate cells 
corresponding to the 4th and 5th layers in man ; B, layer of giant pyramids ; a, b, c, stellate cells 
having long descending axons ; d, e, medium-sized pyramids among the stellate cells. 

with short ascending axon are especially numerous and are characterized 
by being fusiform in shape and by the contact granules which cover the 
cell body and principal dendrites. Besides the existence of cells in the 
cerebral cortex whose axons ascend, but do not make their way into 
the first layer as do those from Martinotti's elements, is the fact that I 
long since discovered while working upon the motor cortex of the small 



Visual Cortex. 341 

mammals; this is, as my latest observations show, that these elements are 
very numerous, and that each cortical layer, or better, that each layer of 
a plexiform aspect, contains a special kind of this element. In addition, 
as we shall see in a moment, these cells form a constant factor in all the 
cortical layers in which nerve fibres incoming from the white matter 
make their terminal arborizations. 

Fifth Layer, ok Layer op Small Stellate Cells. 

This layer, which corresponds to the greater part of the stripe of 
Vicq d'Azyr, when examined in Nissl preparations appears to contain an 
enormous number of small rounded elements which might be mistaken 
for scattered nuclei not surrounded by protoplasm. But in these same 
preparations we may still detect, beside these corpuscles, a few others, 
scattered here and there, of stellate or triangular form and medium or 
large size, very similar to the great stellate cells of the 4th layer. 
Golgi's method reveals to us the great complexity of the 5th layer, and 
by this means we have succeeded in differentiating as many as five kinds 
of elements. The following are the most common types : — 

(a) Stellate Cells of Medium Size. — These are exactly similar to the 
stellate cells of the 4th layer. They are not numerous, and lie irregu- 
larly scattered in all levels of the 5th layer. Their dendrites diverge, 
but run for the most part horizontally, and do not pass beyond the layer 
of their cells of origin. Their axons descend and, after emitting a few 
collaterals to the 5th layer, make their way to the white matter. In 
some cases their collaterals are given off lower down, in the 6th layer, 
and then their course is recurrent, because they must make their terminal 
arborizations between homonymous cells (Fig. 9, g,/}- 

(b) Cells with Ascending Axon. — These are fusiform or triangular, dis- 
posed with long axis vertical. Their axon is similar to that of cells of 
this type in the 4th layer. That is to say, after ascending a certain dis- 
tance it forms a terminal arborization of arching branches distributed 
among the elements of the overlying layer. From its initial portion 
spring a few collaterals which are distributed to the 5th layer (Fig. 13, 
A, £, C). 

(c) Ovoid or Stellate Corpuscles (^properly designated, Granules'). — 
These rarely exceed in diameter more than ten or twelve im. They are 
the most numerous element of the 5th layer. Their soma is ovoid, 



342 



Santiago Ramon y Cajal. 



spheroidal, and even polygonal in form and gives rise to three, four, or 
more fine, smooth dendrites, which terminate, after a short, wavy course, 
within the limits of the 5th layer. Their axons are very delicate and 




Fig. 13. — Cells in the 5th layer with ascending azon, visual cortex of infant aged 15 days. 
A, B, cells whose axons subdivide in the layer of large stellate cells ; C, cells whose axons give rise 
to branches destined for the layer of medium-sized pyramids ; D, cell with arched axon, the initial 
portion of which gives rise to branches for the 4th, 5th, and even 6th layers ; E, very small cells, 
arachniform, with delicate ascending axons; a, axon. 



Visual Cortex. 



343 



take a great variety of directions, — ascending, descending, or horizontal, 
— and finally end in an extended arborization of few branchlets dis- 
tributed exclusively to the very midst of the 5th layer (Fig. 14). 

(c?) Dwarf or Spider-shaped Corpuscles. — Of these there is no lack in 




Fig. 14. — Small cells in the layer of small stellate cells, possessing short diffuse axons (infant 
20 days) . a, cells with delicate ascending axon ; b, c, cells with descending axon ; d, larger cell 
whose axon forms its terminal arborization in the 4th layer ; a, axon. 



344 



Santiago Ramon y Cajal: 



this layer, whose nerve plexus they help to bewilder. Their very tiny, 
often ascending, axon resolves itself very soon into an extremely dense, 




Fig. 15. — Cells with short axons of the layer of stellate cells from the visual cortex of a cat 
aged 28 days, a, large cell whose descending axon subdivides in the deeper level of the Ith layer 
(4th and 5th of man) ; 6, arachniform cell whose axon forms a fine and very dense plexus; d, fusi- 
form cell whose axon is resolved into vertical branches. 

fine arborization close to the cell. In the dense masses of these arbo- 
rizations we notice spaces, which probably correspond to groups of 
granules. 



Visual Cortex. 



345 



The cells with short axons are very abundant in the visual cortex of 
the cat, as may be observed by examining Figs. 15 and 16. Among them 
the more abundant types are : a, fusiform cells whose ascending axon is 
distributed to the superior levels of the layer in question (4th and 5th in 
man) (Fig. 16, 2)); b, large stellate cells with descending axon forming 
their terminal arborizations in the deeper levels of this layer (Fig. 15, a) ; 




Fig. 16. — Elements from the layer of stellate cells of the visual cortex of a cat aged about one 
month. A, B, C, small pyramids with axons arched and ascending; I), large fusiform cells with 
ascending axons ; E, arachniform cells with short axon ; a, axon. 

c, stellate-arachniform cells whose axon forms a most complicated arboriza- 
tion (Figs. 15, b, and 16, U) ; d, bipanicled cells larger than corresponding 
cells in the human brain (Fig. 15, cZ). 

Nerve Plexus of the 4th and 5th layers of the Cortex. One of the chief 
characteristics of these layers consists in the very dense plexus of medul- 
lated fibres extending among their nerve cells. This is formed by two 
kinds of fibres : (1) Exogenous fibres, that is to say those coming from the 
white matter, probably continuations of the cerebro-optic tract. (2) En- 



346 Santiago Ramon y Cajal: 

dogenous fibres, formed by the terminal arborizations of the axons which 
come from cells of the 4th and 5th or the underlying layers. 

Exogenous Fibres. — I have already stated that Gennari's or Vicq 
d'Azyr's stripe corresponds chiefly to the 5th layer, but also includes part 
of the 4th. However, the true composition of this stripe cannot be seen 
in Weigert-Pal preparations, because the hematoxylin stains only the large 
or medium-sized fibres which possess a myeline sheath. Now these fibres, 
as we shall presently see, represent but a very small portion of the com- 
ponents of Gennari's stripes. Very fortunately Golgi's method, applied 
to the brain of an infant at birth or but a few days old, aifords us a very 
clear view of the meduUated and unmeduUated fibres which make up this 
plexus. This method accordingly furnishes us a means of analyzing its 
origin and manner of termination. Permit me to state at the outset that 
the principal contingent of exogenous fibres is represented by a consid- 
erable number of fibres from the white matter, which I shall henceforth 
call, in virtue of their physiological significance, optic fibres. 

The optic fibres are easily distinguished from the axons of the pyra- 
mids by their direction, which is oblique (in some cases they are tortuous 
or even stair-shaped), by their large calibre, often exceeding that of axons 
of the giant pyramids ; finally by the fact that, instead of going to a cell 
as its axon, they repeatedly divide dichotomously, each branch resolving 
itself into a perfectly free terminal arborization spreading almost horizon- 
tally through the extent of the 4th and 5th layers. Fig. 17 reproduces the 
appearance of the optic plexus in a preparation in which it was impreg- 
nated almost alone. I call your attention to the fact that these optic fibres 
send off no collaterals, or very few, in passing through the deeper layers 
(9th, 8th, 7th, 6th), but immediately on reaching the 6th layer their final 
ramification begins. This occurs in many ways. Some fibres divide at 
different levels of the 5th layer into two equal or unequal branches which 
run horizontally to great distances, becoming resolved into a great number 
of collaterals which ramify throughout the entire thickness of the layer. 
Other fibres may be seen which, after giving off a few long collaterals 
during their ascent through the 5th layer, reach up to the extreme limit 
of the 5th layer and here become horizontal. There is no lack of fibres 
which ascend directly up to the limit of the layer of medium-sized pyra- 
mids and there describe arcs, and even very long wavy courses, and end 
by descending, dividing as they descend, through the 4th and 5th layers. 
Finally, from the arching portion of some of these latter fibres fine coUat- 



Visual Cortex. 



347 



erals may be seen to spring on their way to the layer of medium-sized 
pyramids, where they disappear after a few divisions. To sum up, the 
optic fibres terminate al- 
most exclusively within 
the 4th and 5th layers. 
In only two instances 
have I discovered col- 
laterals of optic fibres 
which appeared to form 
their terminal arboriza- 
tions within the 1st 
layer. 

This plexus of optic 
fibres is one of the rich- 
est and densest to be 
found in the gray mat- 
ter of the brain. If it 
is completely impreg- 
nated, which frequently 
occurs in an infant brain 
fifteen or twenty days 
old, it appears as a be- 
wildering meshwork of 
wavy fibres, besprinkled 
with vacant spaces cor- 
responding to the cell 
bodies of these layers 
(Fig. 18, B}. 

I may add that the 

Fig. 17. — Heavy fibres coining from the white substance 

appearance of this ^^^^ subdividing in Gennari's stripe ; visual cortex of infant aged 

plexus diffres a little three days. A, white substance ; B, layer of small stellar cells ; 

. O, arched fibres of Ith layer ; D, border of layer of medium- 

in the two layers (r Ig. gj^g^ pyramids ; a, trunks of the incoming fibres ; 6, collaterals 

18"). In the 4th layer for tlie deeper layers; c, ascending collaterals destined for the 

„, , - more superficial layers. 

its fibres are larger and 

often disposed in arches or horizontal bars, its arborizations are loose 
and separated by ample spaces in conformity to the size of the great 
stellate cells; while in the 5th layer it consists of fine varicose fibrils 
arranged in an extremely dense lattice work with small spaces, corre- 




348 Santiago Ramon y Cajal: 

spondiiig to the small size of the medium-sized stellate cells (Fig. 
18, B}. 

In the preceding brief description I have called the large exogenous 
fibres optic fibres. But what reasons have we to suppose that these 
fibres actually come in from the primary optic centres? We must 
acknowledge, at the outset, that the proof of their optical origin is not 
perfect ; but there is no lack of facts which favor such a view. Some of 
these facts are the following : — 

(a) In the minute brains, as, for example, that of a newborn mouse, 
we can follow these fibres in some cases to the radiation of Gratiolet. 

(6) The fibres which are on their way to Gennari's plexus are very 
large, larger than the axons of the giant pyramids or those of cells of 
intercortical association. 

(c) In the motor cortex we have found that large fibres distributed in 
a similar way actually come in from the corona radiata. 

(c?) In the visual cortex of a man who became blind I have discov- 
ered, by using Nissl's method, a perceptible atrophy of the stellate cells 
of the 4th and 5th layers. A similar case has been recently reported by 
Cramer ; and this fact would seem to point to an intimate union between 
these elements and the act of visual perception, a union whose material 
bond is probably represented by the exogenous fibres of Gennari's plexus. 

(e) Granted that the visual cortex must receive a great number of 
fibres from the radiation of Gratiolet, it is natural to refer to this source 
the fibres which form Gennari's plexus ; since this is the distinctive 
plexus of this region of the brain. 

From the probable fact that the plexus of Gennari's stripe is the 
terminus of the optic fibres, we may draw the important conclusion that 
the cells of the 4th and 5th layers represent histologically the principal 
substratum for visual sensation ; because up to this point in the cortex 
sensory impulses heap up on the centripetal side, and here begin to 
become centrifugal. 

Another conclusion not less interesting follows from it : for an ensem- 
ble of anatomico-physiological facts seem to show that the region of the 
calcarine fissure is not the locus of visual memories, but only that of sen- 
sations of luminosity, and that the residues of the latter must go (in 
order to become transformed into latent images) to other nerve centres. 
We are naturally led to consider the long axon of the 4th and 5th layers 
as the principal, if not the only, path joining these two kinds of centres. 



Visual Cortex. 



349 




Fig. 18. — Nerve plexus of the 4th and 5th layers from the visual cortex of an infant aged 20 
days. A, B, C, respectiyely, layers 4th, 5th, and 6th ; a, trunks of optic fibres ; 6, axons of cells of 
the 6th layer ; c, ascending axons of cells in the 8th layer ; d, bundle of axons descending from the 
medium-sized pyramids ; e, transverse arches of the optic fibres giving rise to ascending collaterals. 



350 Santiago Ramon y Cajal: 

These fibres would function, accordingly, in carrying the copy, or the 
sensory residue, received in Gennari's plexus, to appropriate association 
areas of the brain. Their psychic role is thus a very important one, and 
we should suppose that their interruption would produce psychic blind- 
ness as certainly as the destruction of the occipital lobe itself. 

The plexus of Gennari is well developed in other mammals, but the 
terminal arborizations are never as complicated as in man (Fig. 19). 
Further than this I have not been able to demonstrate any definite differ- 
ences in arrangement at various levels of the layer of stellate cells. How- 
ever, it has seemed to me that the terminal branches, which are very 
varicose, tend to be especially dense in the superficial planes of this layer. 

Endogenous Fibres. — In addition to the large nerve fibres entering 
from the white matter, Gennari's plexus contains either terminal or 
collateral ramifications of fibres which arise in the cells proper of the 
visual cortex. Such are : — 

(1) The very numerous branches from the small cells with short axon 
of the 5th layer. 

(2) The terminal neuritic arborizations of cells with ascending axon 
lying in the 6th, 7th, and 8th layers. 

(3) Arborizations of collateral branches supplied to the 4th and 5th 
layers by the long descending axons of the stellate cells. 

(4) Terminal arborizations from the fusiform or triangular cells of the 
4th and 5th layers which have ascending axons, etc. 

The plexus formed by all the above fibrils is usually finer than that 
of the optical fibres. In order to make out to the best advantage its 
extreme complication throughout its whole extent, we must study it in 
the cortex of an infant from fifteen to twenty-five days old, a period at 
which the terminal arborizations of the visual cells are completely devel- 
oped. It has seemed to me that the endogenous arborizations are more 
numerous in the 4th than in the 5th layer. We may notice also that 
they show a tendency to form true nests surrounding the stellate cells of 
these two median layers. 

Sixth Layer. 

Plexiform and poor in cells in Nissl preparations, it contains a large 
number of small pyramidal or ovoid elements with long axis vertical and 
provided, as may be seen in good Golgi specimens, with a radial trunk 
extending up to the first layer. They have also a few short basilar 



Visual Cortex. 



351 




Fig. 19. — Optic fibres from visual cortex of cat 5 days old. A, bifurcation of fibres a short 
distance from the white matter ; B, nerve plexus in layer of stellate cells (4th and 5th layers 
in man). 



352 Santiago Ramon y Cajal: 

dendrites, descending or oblique and little branched. But the most dis- 
tinctive character of these small elements consists in the course of their 
axons. These descend a short distance, then curve upward and ascend 
through the 6th, 5th, and 4th layers, to which they give a few collaterals, 
and end in a manner which I have not been able to discover. In some 
cases these axons have branched close to their origin and, instead of one, 
describe two arcs continued by ascending fibres. Other axons, more- 
over, make even a greater number of loops. From the convex aspect of 
these curves, as well as from the ascending portion of the axons, within 
the 6th layer spring numerous collaterals which branch throughout the 
entire thickness of the layer. Some descend still further and subdivide 
in the plexus of the 7th layer, that is to say, at the level of the giant 
pyramids (Fig. 20, B). 

Besides these small cells, which are certainly the most abundant, we 
find two other cellular types : (a) Cells of stellate form and medium 
size. They possess radiating dendrites which do not usually pass beyond 
the 6th layer. Their axons ascend and form an arborization throughout 
the extent of the 6th, 5th, and 4th layers. (S) Ordinary pyramidal cells, 
very scarce, of medium or large size. They have precisely the same 
characters as the pyramids of the 7th layer. 

Seventh Layer or Layer of Giant Pyramids. 

Solitary Cells of Meynert. — This layer contains one or two irregular 
and discontinuous files of giant pyramids, which appear, here and there, 
lost as it were in a dense and extended plexus. To this plexus the layer 
owes its finely granular appearance, which may be seen even in prepara- 
tions stained by Nissl's method (Fig. 20, C, and Fig. 22, B). 

The cells in question, like other pyramidal cells, possess a very large 
radial trunk which ends in a flattened spray of horizontal branches in the 
lower levels of the plexiform layer. The cells are also provided with 
a few many-branched basilar dendrites which distribute themselves 
throughout the layer and, finally, with a great number of horizontal 
dendrites forming a plexus which would seem to provide connections 
between these cells through long distances. This is such a characteristic 
feature that by its presence alone we are able to distinguish the visual 
from all other cortical areas. The axon of the giant pyramids is very 
large, extends almost vertically through the 8th and 9th layers, and is 



Visual Cortex. 



353 



continued as a fibre of the white matter. Collaterals spring from its 
initial portion which ramify in the 7th and even the superficial levels of 
the 8th layer. 

In addition to the giant pyramids, which in some cases are not at all 




Fig. 20. — Cells of the 6th and 7th layers from the human visual cortex, infant 15 days old. 
.4,5thlayer; 5,6thlayer; C,7thlayer; a, giant pyramid ; 6, medium-sized pyramid with descend- 
ing axon; c, small pyramid with arched ascending axon; d, pyramid whose axon presents two 
arches ; e, pyramid whose axon gives rise to several arched fibres ; h,f, g, stellate cells with ascend- 
ing axons ramified in the 5th and 6th layers ; i, J, K, pyramids whose axons arch and subdivide 
In the 7th and 8th layers. 

numerous, the 7th layer contains : (a) a number of medium-sized pyra- 
mids possessing the same characters ; (J) several small elements exactly 
similar to those of the 6th layer, the cells with the complicated forked and 
arched axons distributed in the manner above described (Fig. 20, K, i, J) ; 
(<?) in addition may be found medium-sized stellate cells situated in the 
2a 



354 



Santiago Ramon y Cajal : 



7th and 8th layers (Fig. 21, A, B}. The very remarkable feature of the 
latter cells consists in their terminal arborizations. Their neurites take 
at first an ascending or oblique course, divide into two, and then give 
rise to a large number of oblique or horizontal branches which occupy 




Fig. 21. — Special cells of the 7th layer, visual cortex of infant. A, B, stellate cells whose axons 
form terminal arborizations in the layer of giant pyramids ; C, cell with long ascending axon dis- 
tributed to the 4th and 5th layers ; D, giant pyramid of 7th layer ; c, b, axons of small pyramids of 
6th layer. 

a good part of the 7th layer. In the brain at birth their terminals 
present no special peculiarities ; but in one twenty days old I have found 
that a number of these arborizations surround the giant pyramids, form- 
ing terminal nests. Only their arrangement is not so definite here as in 
the motor region, where we find it wonderfully developed. (Compare 
with description below.) 



Visual Cortex. 355 

Eighth Layer. 

Examined in Nissl preparations tliis layer presents a mass of medium- 
sized pyramids and a remarkably dense formation of granules. This is 
the reason Meynert and other writers have called this the layer of deep 
granules or inferior granular layer. 

Golgi's method reveals in this formation elongated cells of pyramidal 
form. They have the radial trunk continued, up to the plexiform layer 
and also descending basilar dendrites which become subdivided and end 
within the 8th layer. Among these there is no lack of fusiform or tri- 
angular cells, but they always present the long radial trunk which we 
find over the whole cortex (Fig. 22, C). 

In general form, it will be observed that these cells resemble true 
pyramids. However, the peculiar behavior of their axons establishes a very 
clear distinction between them. As may be seen in the figure (22, i), 
this axon at first descends, then describes an arc, ascends into the 7th, 
6tli, and 5th layers, and finally ends in a horizontal arborization chiefly 
distributed to the layer of stellate cells, but a few of its branches go to 
the 6th layer. From the loop of the axon, and in the course of its ascent, 
spring several collaterals, which ramify in different planes of the 8th layer. 
In a few of these cells we may observe that, at the bend of the axon, a 
slender branch, similar to a collateral, is given off, which crosses the 8th 
and 9th layers and enters the white matter as a meduUated fibre (Fig. 
22, g). The great majority of these collaterals, however, terminate com- 
pletely within the 8th and 9th layers. At any rate, we must distinguish, 
considering the morphology of their axons, two kinds of cells : (a) cells 
with arched axon none of whose collaterals extend to the white matter ; 
(J) cells whose neurite divides, at the arch, into a fine descending branch, 
which becomes a meduUated fibre of the white matter, and into a larger 
ascending branch with its terminal arborization in the 4th or 5th layers. 

This arched arrangement of the axon in cells of the 8th layer appears 
very strange. It occurs not only in the infant brain, but in the visual cor- 
tex of the adult as well. It seems, at first sight, to violate all laws that 
govern the length and direction of the axons in other sections of the 
nervous system. And, what seems still more remarkable, all these whim- 
sical windings seem to subserve solely the purpose of shortening the 
stretch between the ceU. body and the first collaterals given off by the 
arch. This same phenomenon occurs in many other nerve cells. Were 




Fig. 22. — Seventh and 8th layers, visual cortex of cat, aged 20 days. A, deeper portion of 
layer of stellate cells ; B, layer of giant pyramids ; C, layer of medium-sized pyramids with 
arched axon; a, b, pyramids; c, d, small pyramids with axons distributed to 7th layer; g, tri- 
angular cell, whose axon gives rise to a large ascending collateral; i, another whose axon forms 
an arch and ascends ; 1, pyramid with axon descending to white matter ; j, element from the deep- 
est levels of the layer of medium-sized pyramids (corresponding to layer of fusiform cells in man) 
which gives origin to a large axon that ascends possibly to the 1st layer. 



Visual Cortex. 357 

it not for a deviation from our present theme, I might adduce very con- 
vincing instances of this tendency of the axon to take the direction most 
favorable for the nerve impulses which arise in the cell to very quickly 
reach the elements connected with their initial collaterals. 

Permit me also to add that the 8th layer contains giant stellate 
cells with ascending axon (Martinotti's cells), which runs to the plexi- 
form layer (Fig. 22, j), and also a similar but smaller cell, whose axon 
gives rise to an arborization between the neighboring cells. 

Ninth Layer. 

Coinciding closely with the so-called polymorphic layer of other 
authors, this layer contains elongated elements, fusiform, triangular, or 
ovoid, possessing a radial dendrite, extending up to the plexiform layer, 
and also one or several basal dendrites, which take a descending or 
oblique direction. Finally, these cells have an axon which descends in a 
straight line to the white matter; where, after giving off several col- 
laterals, it continues as a medullated iibre. There are also in the 9th 
layer a few fusiform cells with short radial dendrites and ascending 
axon and a number of stellate cells with short axon of the so-called 
Golgi type. 

In addition, the arrangement of the cells of the 9th layer varies 
greatly in different parts of a convolution. In the convex portion they 
are very numerous, fusiform, and slender, elongated and perfectly radial ; 
while opposite the sulcus they have a quite different form, are stouter, 
more variable, and frequently lie with long axis parallel to the white 
matter, i.e. perpendicular to their ordinary direction. Their peripheral 
processes perform the most whimsical contortions in order to become 
radial and reach the plexiform layer. Their axon appears frequently 
horizontal, describing a very open curve on its way to the white matter. 
All these forms and many others represent adaptations of the cells to 
the foldings of the cortex and to its varying thickness in different parts 
of a convolution. 

I will not impose further upon your indulgent attention with these 
tiresome enumerations of layers and forms of cells, in the mazes of which 
nature herself seems to have intended to lose the investigator and put 
his patience to the test. And I will close this tedious lecture with a 



358 Santiago Ramon y Cajal: 

succinct exposition of the anatomico-physiological inductions that seem 
to follow from my observations on the minute structure of the visual 
cortex of man and the mammalia. 

1. The visual cortex of man and gyrencephalous mammals possesses a 
special structure very different from that of any other cortical area. 

2. The visual region is characterized, above all, by fewness of giant 
pyramids and by presenting, at the level of the granular layer of other 
cortical areas, three distinct layers of cells of special form, to wit : the 
layer of large stellate cells, the layer of small stellate cells, and the layer 
of pyramids with arched ascending axon. 

3. Gennari's or Vicq d'Azyr's stripe contains principally terminal 
arborizations of certain very large fibres, originating probably in the 
primary optic centres (external geniculate body, pulvinar, anterior cor- 
pora quadrigemina). 

4. Since these optic fibres are distributed chiefly to the stellate cells 
of the 4th and 5th layers, it seems natural to consider these elements 
the substratum of visual sensation. 

5. The innumerable cells with short axons in the 4th and 5th layers 
represent, probably, the intermediate links between the optic fibres on 
the one side and the stellate cells of the 4th and 5th layers and the pyram- 
idal cells on the other. 

6. As these intermediate cells are often very small and have short 
axons, it may be that, besides their function of diffusing the incoming 
impulses through the cortex, they play also the special role of augment- 
ing the visual impulses by fresh discharges of nerve force, in order that 
they may reach, in sufficient strength, the cortical regions in which the 
function of commemorative recording of optical images occurs. The 
pathways for conveyance of visual residues from the median occipital 
region to the association centres in the parietal cortex are possibly repre- 
sented by axons of the stellate cells of the 4th and 5th layers. 

7. Granting that the giant pyramids of other cortical regions give 
rise to motor fibres, it would follow that in the 7th layer they possess 
the same function. These cells, whose dendritic trunks come into con- 
tact with the optical plexus, 4th and 5th layers, serve probably to mediate 
the reflexes of the eyeball and head (conjugate movements of the eyes) 
occasioned by elective stimulation of the visual cortex, a theory which 
would seem to be supported by the physiological experiments of Schafer, 
Danillo, Munk, and others. 



Visual Cortex. 359 

8. Granting that each giant pyramid comes into contact in the 4th 
and 5th layers, as well as in the first layer, with fibres that are proba- 
bly associative, we may suppose that motor discharges of these cells can 
be effected by two kinds of impulses : by ordinary optical stimulation 
and by stimuli of a volitional order, possibly coming from the association 
centres and reaching, finally, the plexiform layer. 

My own researches do not furnish grounds for further conclusions. 
Many points still remain to be cleared up; but their complete eluci- 
dation will be the fruit of researches more detailed and exact than those 
I have been able to undertake. 



LECTURE III. 

The Sensori-Motoe. Coetex. 

Aptee the study that we have just made of the visual cortex, we can 
be more concise in our examination of the motor area. In all cortical 
regions we notice general structural characters and special features which 
constitute the physiognomy proper of each cerebral area. Naturally, 
the latter will be of more interest to us, and they will form the subject of 
the present lecture. 

I shall not stop here to give any history of researches undertaken 
upon the minute anatomy of the psycho-motor areas. A bibliography of 
the subject would be very long, tedious, and altogether superfluous, since 
it has already been provided in the recent studies of Retzius, Hammar- 
berg, and Kolliker. It will suffice to name, among those to whom we are 
most indebted for a knowledge of the structure of the motor cortex, Mey- 
nert, Baillarger, Kolliker, Krause, Betz, Lewis, Golgi, Martinotti, Retzius, 
Flechsig, Kaes, Hammarberg, Nissl, etc. All these writers have selected 
the psycho-motor cortex for special study ; and it is safe to assert that 
all our knowledge of the minute structure of the entire cortex has taken 
its character from this region, which some writers have denominated 
" typical." They have done this because it was thought at the time when 
the fundamental works of Meynert and Golgi appeared that in histologi- 
cal structure the whole cortex corresponded to a uniform design, present- 
ing only unimportant variations in different regions. 

Neither have I time to enumerate the layers which have been described 
for this cerebral region. Their number has varied under the pen of each 
writer with the animal and the method he has happened to employ. Thus 
Meynert, who made his observations on man, distinguished five layers ; 
Stieda, Henle, Boll, and Schwalbe limited their number to four ; while 
writers like Krause admitted as many as seven. I myself, at the time of 
my investigations upon the small mammals, recognized four, naming them : 
(1) molecular layer ; (2) layer of small and medium-sized pyramids ; 

360 



Sensori-Motor Cortex. 



361 



(3) layer of large pyramids ; (4) layer of 
polymorphic cells. This number, derived 
particularly from study of the small mam- 
mals, is not valid in the more complicated 
human cortex. To the four classical layers 
of smooth-brained mammals we must add 
one at least, the so-called granular layer of 
Meynert and other writers. This layer, 
situated in its very midst, divides the layer 
of giant pyramids into two, which we may 
call respectively the external, or superficial, 
and the internal, or deep, layers of giant 
pyramids. 

To sum up, the following are the layers 
which it is possible to recognize by Nissl's 
method in the human motor cortex (ascend- 
ing frontal and ascending parietal convolu- 
tions). To conform to our scheme in the 
visual cortex, we have altered the terminol- 
ogy for this region also. 

1. Plexiform layer (layer poor in cells 
of Meynert, molecular layer of some 
writers). 

2. Layer of small and medium-sized 
pyramids. 

3. External layer of giant pyramids. 

4. Layer of small stellate cells (gran- 
ular layer of the authors). 

5. Internal, or deep, layer of giant 
pyramids. 

6. Layer of polymorphic cells (fusiform 
and medium-sized pyramids of certain 
writers) . 

Fig. 23. — Section of adult human motor cortex, 
stained by Nissl's method (semischematic) . 1, plexiform 
layer ; 2, layer of small pyramids ; 3, layer of medium- 
sized pyramids ; i, external layer of giant pyramids ; 
5, layer of small stellate cells ; 6, internal layer of giant 
pyramids ; 7, layer of polymorphic cells or deep pyramidal 
layer of medium-sized cells; 8, layer of fusiform cells. 




362 Santiago Ramon y Cajal: 

These layers correspond particularly to the concave portions of the 
motor convolutions. Over the convexities the gray matter is thickened 
especially at the level of the polymorphic layer, which here appears 
divided into two sub-layers : an external, very rich in pyramidal and 
triangular cells (Fig. 23, 7) ; the other, internal, presenting, besides 
the heavy bundles of white fibres, fusiform cells disposed in parallel 
series (Fig. 23, 8). 

1. Plexif orm Layer. — This is similar in structure in the motor and 
visual areas. It contains, therefore : (1) dendritic arborizations of the 
pyramidal and polymorphic cells, that is to say, of all the cells of deeper 
layers (2, 3, 4, 5, 6) except stellate cells of the 4th layer and the cells 
with short axons scattered through the entire cortex ; (2) terminal arbori- 
zations of the ascending axons of Martinotti ; (3) the ramifications of 
the recurrent collaterals which come up from the axons of certain small 
and medium-sized pyramids ; (4) the fibres, terminal and collateral, which 
arise from the white matter; (5) stellate cells of variable size with 
short axon which ramifies within the 1st layer ; (6) the special, or hori- 
zontal, cells with long tangential dendrites ; (7) finally, neuroglia cells of 
the two well-known types, with long radiating processes close underneath 
the pia (Martinotti, Retzius, Andriesen, Bevan Lewis, et al.^, and type 
with short processes, located at aU levels of the plexiform layer (Golgi, 
Cajal, Retzius, Martinotti). 

We shall not enter upon their descriptive details, since all the struc- 
tiires present the same characters here as in the visual cox"tex. We shall 
merely add that in the motor cortex the plexiform layer is notably thick. 
It also contains a greater number of horizontal cells and terminations of 
the trunks of pyramidal cells (Fig. 25, A, B, C). Its greater thickness 
arises probably, as Lewis remarks, from the extraordinary number of 
pyramidal cells in the und6rl3dng layers. 

2. Layer of Small and Medium-sized Pyramids (Fig. 24, 2 and 3). — 
We shall not stop upon these, because they are so well known. Permit 
me merely to call to mind the fact that their radial trunk, often forked 
near its origin, makes its arborization in the plexiform layer ; while from 
the base springs a fine neurite which, in case of the small mammals, we 
can trace into the white matter. In the child's cortex this is made diflfi- 
cult by the distance, but I have been fortunate on two occasions in fol- 
lowing this axon into the medullary substance, where it was continued 
as a meduUated fibre. The neuritic collaterals are also very numerous 



Sensor ir Motor Cortex. 



563 



and a number of them may be 
seen to recur and make their arbo- 
rizations in the superficial lamina 
of the plexiform layer. 

Cells with Short Axons. — These 
are numerous, although it does 
not seem to me that they are so 
extremely abundant as in the 
visual region. In Fig. 25 I have 
reproduced some of these ele- 
ments which habitually occur in 
my preparations. We remark 
especially: a, a large stellate type, 
whose ascending axon subdivides 
into horizontal or oblique branches 
covering a great extent of the 
layer of small and medium-sized 
pyramids (Fig. 25, K^; b, a second 
type of similar form but whose 
axon forms its terminal arboriza- 
tion very close to the cell (Fig. 
25, E') ; e, still another form with 
horizontal axon the superficial 
branches of which penetrate into 
the plexiform layer (Fig. 25, D); 
d, arachniform cells with axons 
subdivided into dense plexuses 
(Fig. 25, F, a^; e, fusiform, bi- 
panicled cells, which have been 
sufficiently described. 



Fig. 24. — Ensemble of layers of motor 
cortex of infant aged one and a half months; 
Golgl's method (semischematic) . Layers are 
numbered as follows: 1, plexiform; 2 and 3, 
small and medium-sized pyramids; 4, super- 
ficial giant pyramids ; 5, granular or small 
stellate cells ; 6, deep giant pyramids ; 7, poly- 
morphic cells, or deep medium-sized pyramids. 
(In this figure I have not represented the 
deepest portion of the 7th layer.) 




364 



Santiago Ramon y Cajal. 



Having studied all these types and many others in the visual cortex, 
it is unnecessary here to enter upon a more detailed description. One 




Fig. 25. — Cells with short axons of the plexiform and small and medium-sized pyramidal ceU 
layers from motor cortex of infant aged one month and a few days. A, B, C, horizontal cells of the 
plexiform layer ; Z), cell with horizontal axon ; E, large cell with very short diffusely subdivided 
axon ; F, G, spider-shaped cells whose delicate axons form a dense plexus (G) up to the plexiform 
layer ; H, J, bipanicled cells. 

thing concerning the bipanicled cells I may add, viz., that in the motor 
cortex there appear to be two kinds : one, small cells provided with 
slender axon disposed in very delicate vertical pencils (Fig. 25, IP) ; the 



Sensori- Motor Cortex. 365 

other consisting of relatively large cells having very long and thick den- 
drites and with an ascending or descending axon giving rise to terminal 
arborizations of extreme complexity, producing nests or terminal bas- 
kets about the bodies of the small and medium-sized pyramidal cells 
(Fig. 25, J"). Possibly this type, which I take to be a variety of the 
common bipanicled cell, is present over the whole cortex ; but as yet I 
have succeeded in finding it only in the motor convolutions of the infant 
at over one month of age. 

3. Superficial Layer of Giant Pyramids. — Being a continuation by 
imperceptible gradations of the above, this layer contains the well-known 
large pyramids of the writers. In addition to the observations of Betz, 
Lewis, Golgi, and myself, however, I must add a single detail to their 
classical description. The radial process varies greatly as to the extent 
of surface it covers in the plexiform layer. When its dendrites must 
cover a large surface, the trunk forks near the cell, and the two trunks, 
deviating at an acute angle, ascend to give rise to two or more terminal 
sprays, in some cases at considerable distances apart. This amounts to 
saying that certain medium-sized and large pyramids stand related to a 
large number of nerve fibres in the 1st layer, while other cells of the same 
size have more limited connections (Fig. 24). 

In gyrencephalous mammals, dog and cat, the superficial large pyra- 
mids are smaller than in the infant. They might be considered as a sub- 
ordinate element in the layer of medium-sized pyramids. Most frequently 
the only giant pyramids in the cat occur below the granular layer, — a 
layer which, I may add, is very slightly developed in this animal, being 
often blended with the layer of medium-sized pyramids. 

The number of superficial, medium-sized, and giant pyramids is very 
large in the motor area both in animals and man ; and this is one of its 
characteristic features. However, the regions designated by Flechsig as 
association centres possess also a notable number of large pyramids. 
From this feature alone it would be quite difficult to distinguish the 
frontal and parietal from the motor convolutions. 

The axon of the large and medium-sized pyramids descends, as is well 
known, to the white matter and is continued as one or two nerve fibres. 
I must call special attention to the fact that, as shown by my own 
researches, this fibre may fork usually into a fine branch which goes, 
probably, to the corpus callosum and a larger branch to the corpus stria- 
tum. This may be easily observed in the brain of a newborn mouse or 



366 Santiago Ramon y Cajal: 

in one a few days old. It may also be seen that the fibre entering the 
corona radiata passes beyond the corpus striatum, giving off to it a few 
collaterals. It is thus well established that the axon of the large pyra- 
mids is true projection fibre which takes part in forming the pyramidal 
tract. But we must be on our guard about accepting the view of certain 
writers, — v. Monakow, for example, — who ascribe this role, participa- 
tion in the motor tract, exclusively to the giant pyramids, because I have 
demonstrated beyond all doubt, in the motor region of the mouse and 
rabbit, that a number of the axons of medium-sized pyramids and many 
from polymorphic cells also penetrate the corpus striatum. I therefore 
consider as wholly arbitrary all the opinions which tend to attribute an 
exclusive function to elements in each distinct cortical layer. In the cor- 
tical layers, as well as in the ventral horn of the spinal cord, there occur 
together elements with axons of very diverse character and connections. 
The motor cell takes its place beside the associational cell along with the 
element whose axon or collateral goes to the corpus callosum. There 
are, accordingly, in the cortex no " sensory layers " nor " motor layers " ; 
because, as we shall see in a moment, the great majority of the cells 
are related, either by their cell bodies or by their radial trunks, to the 
plexus of sensory fibres. We find thus reproduced the arrangement of 
the spinal cord, where all the cells, or almost all, come into contact with 
sensory fibres of the first or second order, and all represent links in the 
chain of reflex connections. 

4. Layer of Small Stellate Cells ( G-ranular Layer of the Authors). — 
Stained by Nissl's method the layer of small stellate cells appears as a 
great number of nuclei surrounded with little protoplasm which contains 
a few fine granules of chromatin (Figs. 23, 5, and 24, 5). Most of these 
elements, the granules proper, are very small and globular or stellate in 
form. Others, I have observed, are comparable to small pyramids, being 
of triangular form and having a fine radial trunk. Nor is there any 
lack of stellate or fusiform cells of considerable size, which call to mind 
those of the visual cortex. All these elements appear to be mingled. 
However, in certain places I thought I could discover that the small 
globular cells are situated chiefly in the external plane of the layer, whUe 
the minute pyramids were more niunerous in the deeper levels, but there 
are exceptions to this. 

But Nissl's method does not enable us to study the fine processes of 
these elements. To this end we must have recourse to the chromate 



Sensori-Motor Cortex. 367 

of silver method, and by its application — especially in case of an infant 
fifteen to thirty days old, a time at which the reaction is easily obtained — ■ 
I have been able to demonstrate the extreme complexity of the granular 
layer. Good preparations show that it consists of elements with very 
diverse characters, which in spite of their minor differences may be 
classed into two groups : (1) cells with long axons which extend down 
to the white matter; (2) cells with short axons which end within the 
granular layer or in layers above it. 

Cells with Long Axons. — These may be classed into two varieties, 
small pyramidal cells and medium-sized stellate cells. 

(a) The small pyramid is specially numerous in the deep level of the 
4th layer (Fig. 26, A, B}. It has been figm-ed by various Avriters, 
notably by KoUiker, although even he does not give us any information 
on the cliaracter of its axon. The cells are ovoid-pyramidal in form. 
They possess a radial trunk which extends up to the plexiform layer, 
where it ends in a few very slender varicose twigs without contact 
granules. It also has a few tiny descending or oblique dendrites which 
divide repeatedly. Finally, I have very often traced its axon to the white 
matter, in which it is continued as a slender meduUated fibre. From 
its initial portion arise two, three, or four collaterals, some of which curve 
upward to distribute themselves through the 4th layer. In some cases 
the diameter of these collaterals is so large, compared with that of the 
axon, that they might be considered the real axons. 

(6) Stellate Cells. Very hard to stain, and possibly quite scarce. Their 
dendrites arise from the angles of the cell body and run in all directions, 
but are distributed exclusively to the 4th layer (Fig. 26, 2)). Their axons 
spring from the inferior surface, descend almost in a straight line, and, 
after giving off a few large collaterals, very frequently arched and re- 
current, are lost in the white matter. These interesting cells, exactly 
similar to the stellate cells of the visual cortex, are also found in the 
motor cortex of gyrencephalous mammals, although, to judge from my 
own preparations, only in small numbers. Their presence would seem 
to indicate distinctively sensory regions of the brain. 

Elements with Short Axons. — These are also very numerous in the 
infant brain, representing, perhaps, the chief morphological factor of the 
4th layer. Several varieties have been distinguished, of which the most 
common are the following : — 

(a) Stellate or Fusiform Cells of Medium Size. Their dendrites 



368 Santiago Ramon y Cajal: 

diverge in all directions, but chiefly above and below, and end in the 
midst of the 4th layer. Their axon springs from the superior surface, 
ascends for a variable distance, and at varying levels of the layer of stel- 



FiQ. 26. — Cells with long axons from 4tli layer of motor cortex of infant aged one month. 
A,B, 0, small pyramidal cells; D, large stellate cell; E, medium-sized pyramid; a, axon; 6, c, 
large descending collaterals. 

late cells forms an arborization of horizontal or oblique branches of con- 
siderable length and distributed exclusively to the 4th layer. Very 
often the axon branches in the form of a T before proceeding to its ter- 
minal arborization, and from its initial part arise collaterals whose course 



Sensor ir Motor Cortex. 



369 



and terminations resemble those of the terminal branches. These cells, 

we may add, correspond in all points to the cells with ascending axons 

described for the 4th and 5th layers of the visual cortex (Fig. 27, A, (7, D). 

(V) Fusiform, Triangular, or Stellate Cells. These are somewhat 




Fig. 27. — Cells with short axons from 4th layer of motor cortex of infant. A, B, C, cells, stel- 
late or fusiform, with ascending axon divided into long horizontal branches; E, arachniform cell; 
F, cell with axon distributed to layer of medium-sized pyramids. 

larger than the preceding. Their axon ascends to the plexiform layer, 
in which it subdivides and terminates. In its ascent it supplies a few 
collaterals to the 4th and 3d layers. These elements, as we see, corre- 
spond to the so-called cells of Martinotti. In a few cells of this class 
the axon possibly does not reach the first layer, becoming lost in the 
layers below (Fig. 27, A). 



370 Santiago Ramon y Cajal: 

(c) Small Stellate or Spider-shaped Cells. These possess fine and 
richly subdivided dendrites and also a neurite, which forms a very rich 
arborization close to the cell (Fig. 27, E'). 

(i) Bipanicled Cells. These have the characteristics already de- 
scribed in our study of the visual cortex. 

(e) Finally, in the cat and dog I have found a few stellate cells 
with very numerous dendrites, whose descending neurite forms a very 
dense and complicated arborization, for the most part in the 4th layer, 
but in some cases extending down to the deep layer of giant pyramids. 
Possibly these ceUs are homologous to the spider-shaped cells in man, 
which they resemble in the extraordinary richness of the plexus formed 
by the axon. It would then be necessary to suppose, however, that in 
the cat and dog these cells are much larger than in man. 

In order to complete my description, permit me to add that there is 
no lack of ordinary pyramidal cells, in some cases large, scattered irregu- 
larly in the 4th layer (Fig. 26, E'). In mammals like the cat and dog, 
and to a much greater degree in the rabbit, the profusion of pyramidal 
cells obscures our picture of the granular layer. 

Sensory Nerve Plexus of the 4th Layer. — One of the most significant 
facts which I have discovered in the motor cortex is a plexus of very 
large fibres whose numerous subdivisions occupy the 4th layer and 
extend even into the 2d and 3d. They probably enter the cortex from 
the corona radiata. As early as in my first work I called attention to 
these fibres as being different in diameter, direction, and origin from 
axons of pyramidal cells, but at that time I had not succeeded in deter- 
mining the region to which they are peculiar or the precise place of their 
termination in the cortex. My recent researches upon the brain of man 
and also small mammals enable me to add a few details to my description 
of some years ago (Fig. 28). 

First of all, I have been able to determine exactly their origin and 
position in the brain. These are both easy to observe in the brain of a 
rabbit at birth and still better in that of a mouse a few days old. In the 
mouse it may be seen especially well that certain large fibres (called by 
KoUiker, who has confirmed their existence, fibres of Cajal) proceed from 
the corpus striatum, enter the white matter, and often extend horizon- 
tally in it for great distances. In their course they throw off long col- 
laterals, which penetrate into the overlying gray matter. All these 
collaterals, as well as finally the original axon itself, ascend through the 




Fig. 28. — Plexus of heavy sensory fibres from motor cortex of cat 25 days old. A, plexiform 
layer ; B, layer of small and medium-sized pyramids ; C and D, layers of granules and superficial 
layer of giant pyramids ; E, deep layer of giant pyramids ; F, layer of polymorphic cells ; a, fibre 
from white matter ; 6, ascending collateral ; c, varicose terminal arborization ; d, fibre directed to 
the plexiform layer, which appears to be distinct from the large fibres. 



372 Santiago Ramon y Cajal: 

polymorphic layer, dividing once or twice, then, passing obliquely through 
intervening layers, form an arborization of heavy fibres vrithin the layers 
of small, medium-sized, and large pyramidal cells. However, in the rat 
and rabbit these branches are most numerous in a relatively superficial 
plane, which corresponds probably with the granular layer of the human 
brain, — a layer that is not differentiated in the small mammals. We 
also find a relatively small number of branches that ascend to the 
plexiform layer. As to the cortical distribution of this plexus, we 
may also place on record a fact of interest. It never covers the whole 
cortex. It begins to appear some distance from the median fissure and 
disappears below long before reaching the olfactory area or limbic lobe. 
I have never observed it in the cortex of this sulcus, nor in the anterior 
portion of the frontal lobe, nor even in the region of the auditory or 
visual centres. 

I shall return to this matter in a future investigation, for I think it 
merits most thorough study ; because, if it can be confirmed in a positive 
manner and by other methods, we shall possess a criterion by which to 
distinguish between areas of association and projection in the cortex. 
The projection areas will probably be found to be not, as Flechsig thinks, 
those possessing fibres that go to the corpus striatum (since Dejerine 
and others have discovered these fibres in the so-called association 
centres) but those receiving sensory fibres. At the same time, the 
association centres will be characterized by the absence of these direct 
sensory connections. At any rate, I believe that even in the brain of the 
smallest mammal there are areas, of small extent it may be, specialized 
to store up the images or residues of the sensory projection centres. It 
would be most astounding if the brains of the small mammals possessed 
a different architecture from that of man, taking into consideration the 
fact that all the senses have the same essential structure in all mammals 
and that memory — visual, tactile, muscular, etc. — is just as necessary to 
their lives as to our own. 

The sensory plexus is highly developed in gyrencephalous mammals 
and in man. I have found it well impregnated in the brains of infants 
at birth and a few days old. Here it appears made up of large fibres 
having an oblique direction and a flexuous or even staircased course. 
After dividing several times in the 6th and 5th layers they give rise to a 
singularly extended arborization of horizontal fibres distributed chiefly 
to the layer of granules or small stellate cells. We thus see in the motor 



SensorirMotor Cortex. 373 

cortex, as was the case in the visual, that the layer of granules is the 
principal focus of sensory impressions. From this terminus they are 
propagated by the numberless cells with short ascending axons to the 
layers above and especially to the medium-sized and giant pyramids. 
However, it must be acknowledged that the sensory plexus is not so 
narrow and well defined as the optic. For, although its greatest density 
occurs in the 4th layer, its terminal branches divide in their ascent 
to the superficial layer of medium-sized and giant pyramids. The fibres 
which extend up to the small pyramids in man are not numerous. It is 
for this reason that I cannot agree with Bevan Lewis in ascribing to 
them sensory functions. I do not wish to be understood to deny the 
sensory function of the small and medium-sized pryamids. According to 
my view, all the cells of the motor cortex are sensory because they all, 
possibly, come into contact either directly (cells of the 3d, 4th, and 
6th layers) or indirectly, through the intervention of cells with short 
axons, with sensory terminal arborizations. But, since some cells send 
their axons to the pyramidal tracts, we are able to distinguish them 
as sensori-motor cells of the first order. The others, which send their 
neurites to other motor areas of the brain, possibly effect contact with 
sensori-motor ceUs of the first order located elsewhere. These cells of 
indirect sensori-motor communication we may be warranted in calling 
sensori-motor cells of the second order. It goes without saying that this 
distinction is purely hypothetical ; for no method enables us to determine 
the precise point within the brain where the axons of the pyramidal tracts 
of the corpus callosum or of bands of association fibres form their terminal 
arborizations. 

5. Layer of the Giant and Medium-sized Pjrramids. — In the adult 
human brain stained by Nissl's method, a section of the motor cortex 
reveals, below the granular layer, a layer of plexiform or granular aspect 
filled very thickly, but in no particular order, with a few giant and a 
great number of medium-sized pyramids (Fig. 29). 

Usually the giant pyramids are located near the 4th layer, forming 
there a few irregular ranks. Impregnated by Golgi's method, they 
appear similar to the same cells in other regions of the cortex, but differ 
in a few particulars. The body is generally conical, very much elon- 
gated, giving rise at the apex to a large trunk, often dividing near the 
cell, which terminates in the 1st layer in the usual manner. A group 
of long complicated dendrites diverges from its base, and from the sides 



374 



Santiago Ramon y Cajal . 



spring several very long horizontal processes which subdivide into ter- 
minal brushes, and these, intertwining with similar structures from 
neighboring cells of the same level, form a dense and very characteristic 




Fig. 29. — Deep layer of giant pyramidal cells from motor cortex of infant aged 20 days. 
A, B, pyramidal cells ; D, C, elements with short axons. 

protoplasmic plexus. It is the same arrangement we already know so 
well in the visual cortex, except that, instead of one plexus, there are 
many. The axon is large and, after giving off very long collaterals to 
the 5th and 6th layers, it passes on to become a medullated fibre of the 
white matter. 

The medium-sized pyramids are very numerous, much scattered, and 



SensorirMotor Cortex. 375 

occur in greatest profusion in the lower levels of the layer. They do 
not differ in character from the giant pyramids, except as to the lateral 
somatic dendrites, which are few and not characteristic. 

Besides the pyramidal cells the 5th layer contains a few other kinds 
of elements. From the point of view of their morphology the following 
are the more striking types. 

(a) Oells which form Terminal Nests. — These cells, very similar to 
those which give rise to the basket fibres of the cerebellum, are most 
numerous in the 5th layer between or below the giant pyramids. I have 
found them also in the layer of granules or small stellate cells. 

Their volume is small, similar to that of a small pyramid, and in form 
they appear stellate or triangular with very long and much-branched 
varicose dendrites. The neurite, however, presents the most distinctive 
feature. It ascends, forking close to its origin, and breaks up into a 
ramification of very many branches, ascending, oblique, or horizontal. 
After a few subdivisions, all these branches make their way to the giant 
and medium-sized pyramids to form very complicated varicose arboriza- 
tions close around their cell bodies and principal processes, after the 
manner of the terminal baskets of the cerebellum or the nests found in 
Deiter's nucleus. Each nest contains arborizations from several cells, and 
each basket cell helps to form a large number of nests (Fig. 30, d'). 

(5) Cells with a Diffusely Branched Ascending Axon. — This is a 
fusiform or stellate cell located at different levels of the 5th layer, to 
which it sends its dendrites. The axon ascends to the superior limits of 
the layer where it forks, and its terminal branches form a loose horizon- 
tal arborization of an enormous extent and connected probably with the 
deep giant pyramids (Fig. 29, C, D). 

(c) Small Pyramids with Arched Axons. — This cell, which I have 
studied particularly in the motor cortex of the cat, is entirely similar to 
the element which we found in the 6th and 7th layers of the visual 
cortex. The cells possess a fine dendrite which ascends to the first layer, 
where it ends in a very modest and delicate arborization. Their axon 
descends and, after giving off a few relatively long recurrent collaterals, 
appears to fork and end in the midst of the 5th layer. The branches 
which spring from the bend of the arch descend in some cases, but I have 
not been able to trace them down to the white matter. 

(c?) Cells with Long Ascending Axon. — These are fusiform or tri- 
angular cells with long polar dendrites which never reach the first layer. 



376 



Santiago Ramon y Cajal . 



Their axon arises from the superior surface of the cell, and, after giving 
off a few branches to the 5th and 4th layers, it continues its ascent to the 
plexiform layer and there makes its terminal arborization. 

6. Layer of Polymorphic Cells. — This layer contains the same elements 
as the layer of the same name (9th) in the visual cortex (Fig. 31), that 




Fig. 30. — Pericellular terminal arborizations from tlie deep layer of giant pyramids, motor 
cortex (ascending frontal convolution) of infant aged 25 days, a, axons giving rise to oblique 
and horizontal branches ; b, c, d, terminal nests. 

is to say, fusiform cells with two long polar dendrites, triangular cells, and 
true pyramids. Their axons all go to the white matter. Their ascend- 
ing trunks, which are never lacking, become very attenuated on account 
of the branches given off while passing through the 4th layer and reach 
the 1st layer as an exceedingly delicate fibril, which ends in a fine, 
slightly extended, notably varicose dendritic spray. 

In Fig. 31, I have reproduced the principal types of cells found in the 
polymorphic layer. Besides the medium-sized pyramidal and triangular 
types having long descending axons (Fig. 31, A, B), there occur other 



SensovirMotor Cortex. 



377 



forms in great numbers. These are fusiform or triangular cells whose 
axons penetrate into the superposed layers, furnishing to them a great 




Fig. 31. — Principal types of polymorphic cells from motor cortex of infant aged 20 days. A, B, 
cells with long axons extending to white matter ; C, D, E, fusiform cells with ascending axon ; H, 
giant stellate cell. 

number of branches. Some of these axons seem to end in the deep layer 
of giant pyramids, but others appear to pass beyond this. Finally, there 



378 Santiago Ramon y Cajal: 

is no lack of arachniforra cells (Fig. 31, J), cells with short axon of the 
sensory type of Golgi, whose axons form terminal arborizations in the 
layer under consideration. I may add that I have found in two cases 
giant stellate cells with heavy horizontal axon which gives off collaterals 
(Fig. 31, H^. I do not know the ultimate fate of this process and am 
imable to say whether these scattering cells form a constant feature of the 
motor cortex. 



Cortex of Acoustic, Olpactoby, and Associational Aeeas. 

Unfortunately, my own researches are not as yet in a very advanced 
state in regard to these important cortical centres. So that any in- 
formation that I can give must necessarily be fragmentary and of little 
value. 

The acoustic resembles exactly the motor cortex as to general 
arrangement of cells and layers, but differs from it in a few pecu- 
liarities : (1) by the fineness of the fibres forming the plexus at the level 
of the layer of granules or small stellate cells ; (2) in the profusion of 
bipanicled cells with their very delicate and complicated neuritic brushes ; 
(3) above all, by the presence of certain special cells scattered irregularly 
through the entire thickness of the cortex. The very large axon of these 
special cells extends in a horizontal or oblique direction, but I have not 
yet been able to determine exactly its manner of termination. These 
large cells are fusiform and lie horizontally. From their polar dendrites 
spring a number of fine ascending branches, which subdivide repeatedly 
but do not extend up as far as the plexiform layer. 

The olfactory cortex, that of the limbic lobe, is characterized by the 
following peculiarities : (1) the enormous development of the plexiform 
layer and the presence in it, in addition to its usual structures, of the 
antero-posterior fibres that come from the external root of the olfactory 
tract ; (2) the absence of the layers of small pyramids and granules ; 
(3) the presence of certain large horizontal cells below the plexiform 
layer ; (4) the peculiar form of the medium- and large-sized pyramids 
which emit from the deep end of the cell body a brush consisting of 
numerous much subdivided dendrites ; (5) above all, the fact that the 
sensory plexus, i.e. the fibres which come from the olfactory bulb, makes 
its terminal arborization exclusively in the plexiform layer and in the 
most superficial portion of that layer, corresponding to that of the small 



Sensorir Motor Cortex. 379 

pyramids. This significant fact, brought to light by the studies of 
Calleja, shows us that the sensory fibres do not end in the same level 
of the cortex in all regions. Hence, the layer specialized to serve as 
substratum for the phenomena of sensation may change its position in 
different sensory areas. 

Our task is now drawing to its close. My work upon the topo- 
graphical structure of the cortex has been fragmentary and leaves 
much to be desired. Many things, in fact, are still undiscovered. But, 
despite the very incomplete state of my researches and the narrow 
limits of the field they cover, I may draw a few anatomico-physiological 
conclusions, of which the chief are the following : — 

And first, as to the hierarchy of centres in the cortex of the human 
brain, comparing it with the mammalian brain, we may call to mind that, 
while it does not contain wholly new elements, it presents very distinc- 
tive characteristics, to wit : — 

1. The enormous development of the horizontal cells of the plexi- 
form layer and the considerable length of their so-called tangential 
fibres. 

2. The great abundance of cells with short axons scattered through- 
out the whole cortex, cells which form special varieties by reason of 
differences in their forms and the directions of their axons. 

3. The presence of cells with short axons, very slender (bipanicled 
spider cells), with terminal arborizations whose delicacy is not approached 
by anything found in any animal. 

4. The considerable development of basilar dendrites of the pyram- 
idal cells. 

5. The presence among the mid-layers of the cortex of a formation 
of so-called granular cells, a kind of focus occupied by enormous num- 
bers of pyramids with short axons descending, arched, and ascending. 
This granular formation is present in gyrencephalous mammals, but in 
them it is very poor in cells with short axons and in small pyramids. 
In the smooth-brained animals it is almost wholly lacking. 

The human cortex has evolved, accordingly, along three different 
lines : by multiplying cells with long axons and, above all, those with 
short axons ; by decreasing the volume of cells and the diameter of cer- 
tain fibres in order to make possible within the limits of space a deli- 
cate and greatly improved organization ; finally, by varying and infinitely 



380 Santiago Ramon y Cajal: 

complicating the external morphology of the nerve elements, undoubt- 
edly with the purpose of multiplying, in correspondence with their 
complexity, functional associations of all kinds. 

As to differences and analogies in regional structure, the following 
propositions may be regarded as established : — 

1. The sensory as well as the so-called associational areas are made 
up by a combination of two orders of structural factors. The first 
order consists of common factors, which show very little modification. 
They are represented by the plexiform layers and the layers of pyram- 
idal and polymorphic cells. The second order comprises special fac- 
tors, structures peculiar to each cortical area. Their chief anatomical 
feature resides especially in the granular layer and is related mainly 
to the presence of particular centripetal fibres and of special types of 
cells with long axons (stellate cells of different kinds). 

2. It seems probable that the common factors perform functions of 
a general order concerned, possibly, with ideas of representations of 
all kinds of movements related to the special sensations of which the 
cortical region is the seat. It seems also probable that the special 
anatomical factors of the sensory areas perform the function of elab- 
orating specific sensations (sensation of seeing, hearing, etc.) and also 
of conveying sensory residues to the so-called association centres, where 
they may be transformed into latent images. 

3. Each sensory cortical centre receives a special category of nerve 
fibres (fibres of central sensory tracts). Their cells of origin, as has been 
shown by the researches of v. Monakow, Flechsig, v. Bechterew, and 
many others, reside in the particular nuclei of the medulla, corpora quad- 
rigemina, and optic thalami. It is precisely the presence of these sen- 
sory fibres of the second order that constitutes the prime anatomical 
characteristic of the centres of sensation or projection. 

4. The absence of these sensory fibres, which come from the corona 
radiata, may be used in all mammals to distinguish the so-called associ- 
ation centres. These centres, which exist even in the mouse, also have a 
nerve fibre plexus distributed among their median layers (layer of gran- 
ules in the association areas in man). The fibres, however, which consti- 
tute them are very fine and appear to come from sensory centres of the 
brain. Possibly the cells about which these sensorio-ideational fibres 
terminate represent the substratum or, at any rate, the first link in the 
chain of nerve elements whose function is the representation of ideas. 



Sensor 'ir Motor Cortex. 381 

5. Since we have seen that each aiferent fibre in the sensory cortex 
comes into contact with an extraordinary number of nerve cells appar- 
ently scattered without any order, we must suspect that these relations 
conform to the preconceived design of a well-determined and constant 
organization. 

As, at present, it seems to be impossible to discover these relations, 
we may surmise that each sensory fibre comes into contact, directly or 
through other cells, solely with those pyramids whose stimulation is nec- 
essary in order to effect, after the manner of the reflex arc, movements 
coordinated and intentional. We may also surmise (supposing that the 
stellate cells of the tactile and visual cortex form the link between the 
sensory and ideational centres) that each sensory afferent fibre, bringing 
a unit of sensation (the impression received by a cone of the retina or by 
the terminal arborization of any peripheral nerve fibre), enters into rela- 
tion exclusively with the group of nerve cells entrusted with the func- 
tion of conveying this impression to a particular point in the associational 
cortex. 

Many other hypotheses are possible, but I must conclude for fear of 
tiring your kind and sympathetic attention and exhausting your patience. 
I fear that I have already made too free use of hypotheses and have pre- 
tended to fill the gaps of possible observations with arbitrary supposi- 
tions. 

It is a rule of wisdom, and of nice scientific prudence as well, not to 
theorize before completing the observation of facts. But who is so 
master of himself as to be able to wait calmly in the midst of darkness 
until the break of dawn ? Who can tarry prudently until the epoch of 
the perfection of truth (unhappily as yet very far off) shall come ? Such 
impatience may find its justification in the shortness of human life and 
also in the supreme necessity of dominating, as soon as possible, the phe- 
nomena of the external and internal worlds. But reality is infinite and 
our intelligence finite. Nature and especially the phenomena of life show 
us everywhere complications, which we pretend to remove by the false 
mirage of our simple formulse, heedless of the fact that the simplicity 
is not in nature but in ourselves. 

It is this limitation of our faculties that impels us continually to 
forge simple hypotheses made to fit, by mutilating it, the infinite uni- 
verse into the narrow mould of the human skull, — and this, despite the 
warnings of experience, which daily calls to our minds the weakness, the 



382 Santiago Ramon y Cajal: Sensorir Motor Cortex. 

childishness, and the extreme mutability of our theories. But this is a 
matter of fate, unavoidable because the brain is only a savings-bank 
machine for picking and choosing among external realities. It cannot 
preserve impressions of the external world except by continually simpli- 
fying them, by interrupting their serial and continuous flow, and by 
ignoring all those whose intensities are too great or too small. 

I cannot conclude this, my third and last lecture, without a word of 
tribute to this great people of North America, — the home of freedom and 
tolerance, — this daring race whose positive and practical intelligence, 
entirely freed from the heavy burdens of tradition and the prejudices of 
the schools, which weigh still so heavily on the minds of Europe, seems 
to be wonderfully endowed to triumph in the arena of scientific research, 
as it has many times triumphed in the great struggles of industrial and 
commercial competition. 




Z?>2 






/i'^y. -/ 




PSYCHIC PEOCESSES AND MUSCULAE EXEECISE. 

By Professor Angelo Mosso. 

First, let me give expression to my gratitude to Clark University, 
whose invitation made it possible for me to take part in this celebration. 

To the American schools of psychology, a subject which in Europe 
forms so characteristic a branch of the development of science, we are all 
deeply indebted. Psychology is a fertile field, where philosophers and 
scientists can unite for common labor, a field, indeed, where they cannot 
be separated from each other, for here the idealists and the empiricists 
are held together by a common bond, laboring, as they all are, at the 
solution of the greatest and the most difficult of all problems — the inves- 
tigation of the human mind. 

Clark University, moreover, can boast of having given to pedagogy 
also a new impulse. Many excellent teachers come hither to perfect 
themselves for their profession. I may be permitted, therefore, to make 
both fields, psychology and pedagogy, the subject of my lectures, which 
will treat of the relations existing between the psychic processes and 
muscular exercise. 

I. 

It had long been known that our brain has at birth a grayer hue, and 
only later takes on a whitish color. This whitish color originates from 
the fact that the cerebral nerve fibres, after their complete development, 
are surrounded by a sheath which has this color. 

To Paul Flechsig ^ is due the great credit of having shown that our 
cerebral nerve fibres are not complete at birth, and that the white nerve- 
paths come from the medulla, extending from the periphery toward the 
centre. 

In man, the brain develops later than in all the other animals, because 
his muscles also develop later. The striped muscles are more incomplete 
at birth in man than in any other animal. For this fact, that the human 
brain develops so slowly, I am able to discover no other reason than 

383 



384 Angela Mosso : 

this, that at birth the organs which effect movement, over which the brain 
later exercises its authority, are not yet complete. 

The muscles of the adult human being are thirty-seven times as heavy 
as those of the newborn child, while the brain of the former is only 
3.76 times as heavy as that of the latter. 

It had been long known also that the brain of man slowly increases in 
weight up to the fortieth year. Recently Kaes ^ has shown that, up to 
the fortieth year, there are formed in the cerebral convolutions new plex- 
uses of nerve fibres, which are lacking in younger brains. 

Excitation of the senses and impulses to movement hasten the devel- 
opment of the nerves in question. The experiments of Ambronn and 
Held^ have shown that, if one eye of a newborn kitten is opened to 
the light, the other remaining closed, the optical fibres of the eye which 
is stimulated by the light are more quickly surrounded with myelin than 
those of the other. Another important fact is that the motor nerve 
fibres are complete earlier than the sensory. 

These facts we must apply to pedagogy. Only that science can show 
how injurious is precocious instruction for the development of the child. 

If we wish to hasten the maturity of the brain, we must decide whether 
the formation of the myelin can better be hastened by stimulations of the 
senses and intellectual work, or better by muscular exercises. The latter 
way seems to me the more natural. We must, therefore, to begin with, 
consolidate the motor nerve paths which develop first, and after that seek 
to develop the portion of the brain concerned with intellectual work. 
Modern views show a tendency to confirm what the great philosophers of 
Greece already recognized, viz., that children ought to begin to read and 
write only with the tenth year. The conviction is again slowly maturing 
that our children begin to learn too early, that it is injurious for the 
development of the brain to be fettered to the school-desk when only five 
or six years old. The conviction is slowly making its way that no more 
time should be devoted to intellectual work than to muscular exercise. 
The modern education of youth, however, resembles more an artificial 
hothouse culture than a natural training of the human plant. 



The fact observed by me that in man the phenomena of intellectual 
fatigue are identical with those of muscular fatigue, caused me to inquire 
whether or not the conscious processes and those of movement are identi- 



Psychic Processes. 385 

cal processes, which take place in like cells, or, perhaps, alternately in one 
and the same cell. 

The new phrenology exhibits a tendency to localize the mental func- 
tions, but the old idea, which distributed the nervous functions over the 
whole cerebral cortex, does not yet acknowledge its defeat, and what I 
have to say to-day will show that there exists an intimate connection 
between the conscious processes and muscular exercise. 

Doubtless, there are regions known in the brain which are traversed 
by the will impulse which sets certain muscle groups in motion, but they 
are the junctions of roads, they are the tracks upon which the trains run, 
not the stations where the trains are formed, and where they receive the 
will impulse. In fact, in cases where it was possible to stimulate electri- 
cally the motor region of the human cerebral cortex, the subject declared 
that he felt, in that part of the body in which the current caused a mus- 
cular contraction, sensations which resembled the creeping or running of 
ants. 

If the so-called motor region of the brain is destroyed, it is found that 
a change of sensibility also takes place. These facts suffice to show that, 
up to the present, no absolute local separation of movement and sensibil- 
ity is demonstrable. Moreover, all agree that every will impulse is joined 
to the idea of the movement to be executed. 

If, in a monkey, the roots of the sensory nerves which go to the arm 
are severed, the animal no longer moves the hand spontaneously, although 
the voluntary nerve paths are uninjured, because the uhi consistam of 
sensibility is lacking. Our mechanisms are so complete that the move- 
ment-command is never given by the cells without a clear idea of the 
place where it is to be carried out. 

In every voluntary movement there exists between the periphery and 
the centre such an intimate connection that patients who have lost the 
muscle sense can contract the muscles of the hand around an object and 
keep them contracted, as long as they look at the object. So soon, how- 
ever, as they turn their eyes away, the muscles instantaneously relax. For 
a movement impulse to express itself, it must be controlled by the sensory 
nerves ; for the will and the sensibility are functions inseparably con- 
nected with each other. 

m. 

Attention, which has been called an internal sense, shows really in the 
best way how isolation from the influence of the external world is possi- 



386 Angela Mosso : 

ble in the study of psycliic phenomena. Attention is the most intense 
activity of the mind, and yet we all know that we are not capable of 
absolutely controlling it. The more or less favorable disposition for 
intellectual work, which we perceive on certain days and at certain hours, 
awakes the suspicion that attention itseK is, to a great extent, conditioned 
by internal reflex phenomena. 

I have already shown in my writings * that, in a state of attention, the 
respiration becomes slower and deeper, the blood-vessels in the forearm 
and in the foot contract, the blood flows more abundantly to the centre, 
the form of the brain and arm pulse changes, and the activity of the heart 
is increased. 

In the state of attention, moreover, there exist an increased secretion 
of sweat, a greater consumption of the organism — the blood is poisoned 
by the products of intellectual fatigue.^ 

Attention produces not only the same chemical effects and the same 
fatigue as muscular exertion does, but we feel also, when we are attentive 
to anything, the characteristic muscular strain on the occiput, the fore- 
head, and other parts of the body. 

One of the characteristic phenomena of attention is its periods, which 
have been so well studied by Wundt and his pupils, — periods which 
exhibit a great resemblance to those observed by Dr. W. P. Lombard® 
in the case of continued muscular contraction. Under the direction of 
Dr. G. Stanley Hall, Lindley^ has investigated the involuntary move- 
ments which we make when we think of anything, muscular contractions 
of the face, hands, and feet. These movements are like those which we 
make during muscular exertion. 

We cannot force the attention to fix itself upon one object contin- 
ually, because it quickly becomes exhausted, and renews itself only when 
a new object is offered it, when new paths for its activity are opened. 
It is not we who direct the attention. We can only indicate to it the 
direction which it is to take according to our wishes. After that it is 
free and does what it pleases ; it flits about like a butterfly on the path 
which we have pointed out for it. 

The excitability of artists, the peculiarity of their character, show that 
in them the involuntary movements are more easily executed, and that 
intelligence and mobility increase together. But the fact that artists see 
objects in a particular way, and that the thing seen by artists, like that 
seen by litterateurs, is retained by the memory in very characteristic fash- 



Psycliic Processes. 387 

ion, proves that attention works in a different way with them. The 
plastic talent of southern peoples, the ease of their movements, their more 
lively gestures, the more intense expression of their emotions, disclose to 
us the nature of the artists' genius. I believe, however, that there is also 
contained in attention an emotional factor. 

Great impressionability and the capacity to fix the attention for a 
longer time are, doubtless, two of the chief conditions for artistic genius. 
But I believe also that the exercise of the hands exerts an influence upon 
the development of the mind. 

During the first epoch of the Renaissance, the greatest artists of 
Florence were all apprentices in the workshops of the goldsmiths. Luca 
della Robbia, Lorenzo Ghiberti, Filippo Brunelleschi, Francia, Domenico 
Ghirlandajo, Sandro Botticelli, Andrea del Sarto, — to mention only a few 
examples, — performed, during their apprenticeship, the simplest labors 
in the workshop of a goldsmith. But the exercise with which they 
gained their manual dexterity surely influenced also the development 
of their genius. 

In the beginning of the sixteenth century this school ended, but from 
the pedagogical standpoint it is still worth studying. If I may be per- 
mitted to express an opinion, I would say that the manual dexterity 
favored by this labor contributed much to the development of the great 
masters of genius. 

A fact which cannot be doubted is the manysidedness of genius which 
some Italians of the Renaissance possessed, and which has never again 
appeared with like copiousness. 

Giotto was painter, sculptor, and architect. Leonardo da Vinci was a 
celebrated musician, a great painter, an engineer, an architect, a man of 
letters and of science. Andrea del Verrocchio was goldsmith, sculptor, 
engraver, architect, painter, and musician. These facts are to be read in 
many histories of art. An incomparable example, however, is Michel- 
angelo. For twelve years he studied anatomy on the cadaver, and after- 
wards painted the Sixtine Chapel and executed the tombs of the Medici 
and the dome of St. Peter's. 

In the artist, better than in other human beings, is seen the inti- 
mate connection between the psychic processes and muscular exercise. 
Power of resistance against fatiguing labors, dexterity, and capacity 



388 Angelo Mosso : 

for concentration, are the secret of their marvellous life. I am con- 
vinced that muscular movements have formed the omnipotence of genius, 
just as, vice versd, intellectual exercises effect advantageously the develop- 
ment of the muscles. Michelangelo ground his colors himself. Raphael, 
while as an engineer in Rome he carried on excavations and painted 
the rooms of the Vatican, wrote a treatise on how the smoking of 
the chimney in the kitchen of a prince might be prevented. As Vasari 
relates, Perino del Vaga made every mechanical object; he fabricated 
often trumpeters' pennons, portieres, drapery, flags, embroidery, and carv- 
ing, and painted sarcophagi. He was a great painter, and his stucco 
works belong to the most valuable of the Renaissance period. Even if 
the genius of these mighty men will remain a secret for all time, yet 
we can say this much, that their hand was just as dexterous as their mind 
was lofty. 

These men, who are the greatest representatives of our race, have 
carried the dexterity of their hands to the highest degree of perfection. 
They were simple workers, who, laboring untiringly with their hands, 
lifted the human mind to the highest ideals of beauty. 

If the Greeks excelled all other peoples in genius, it was because they 
paid more attention than did the others to bodily exercise ; they brought 
gymnastics, the study of bodily positions and bodily exercise, to a height 
which has never been reached by other peoples since their day. 



Our brain possesses probably more substance than we generally use, 
so that a not inconsiderable part of it may be looked upon as an organ of 
luxury. The fact observed by me, that we breathe in more air than is 
necessary, together with the fact observed much earlier, that we eat much 
more than we need, allows us to designate as luxury all that is not abso- 
lutely necessary. 

Our brain has on the average about a milliard of nerve cells. Many 
men have more, and others less brain substance, without it being possible 
to detect a difference in the intensity of their psychic processes. 

Large and heavy brains are often found in men who do not make full 
use of them. Such a brain was that of Rustan, which Rudolphi has 
described. It weighed 2222 gr., while that of Helmholtz^ weighed 
only 1420 gr. The brain of the unknown, commonplace individual, 
Rustan, was therefore 802 gr. heavier than that of Helmholtz. The 



Psycliic Processes. 389 

great facility with which, in the case of partial destruction of the brain, 
the individual parts can substitute one another has been demonstrated 
by Flourens and Goltz. 

Not all the brain cells work simultaneously, but they relieve one 
another probably with such punctuality that only under certain conditions 
do we notice that some groups are fatigued. 

That this relief process exists can be argued from the fact that the 
nerve cells offer only a very small resistance to fatigue. 

The attention itself works in periods of activity and rest. These 
periods have been observed in the case of the sense of sight, as well as in 
the senses of hearing, taste, and touch. Since, as Bowditch has shown, 
the nerves, as such, do not become fatigued, we must ascribe such fluctua- 
tions to the centre. 

If we close one e3'-e, and with the other look at an equally illuminated 
wall or the sky, we notice that the visual field now darkens, now lights 
up again. ^ The dark color becomes green, yellowish, or blue, and appears 
in regular intervals, 5-12 times a minute. These periods vanish as 
soon as the eye in attention is directed towards a certain object. 
I do not believe that this phenomenon arises from the movement of the 
blood-vessels, for it appears only when we look with one eye. I am of 
the opinion that it points to a relief -process in cerebral activity, and to a 
period during which a slight fatigue of the brain cells takes place, if the 
latter are not incited by the attention to more intense labor. Our atten- 
tion turns automatically now to one, now to the other eye.^" 

There exists a remarkable agreement between the periods of activity 
and rest of the brain cells and of the sympathetic system. If we investi- 
gate the movements of the blood-vessels with the plethysmograph,ii and 
also the movements of the bladder,^ we notice great undulations, coincid- 
ing with some respiratory movements. In the curves also, observed in 
man and animals when the blood pressure is investigated, these fluctua- 
tions, which were first described by Traube, are seen. I myself have 
shown that the respiratory curve exhibits periods of greater and less 
activity. These fluctuations are particularly characteristic in mountain 
sickness. "With each period of rest the excitability of the nervous centres 
is decreased. 

From all these phenomena it seems to follow that the nerve cells have 
only a small power of resistance, and that they show on the average every 
ten seconds a tendency to rest. 



390 Angela Mosso : 

I have further been able to show, by means of the ergograph, that to 
strongly contract the hand suffices to induce in the brain the first symp- 
toms of fatigue, and that a few seconds of rest are enough to make the 
nerve cells capable of functioning again. 

The very short duration of the capacity to resist in the nerve cells 
makes it plain that the brain must necessarily possess a great number of 
cells. It is the task of pedagogy to show how the brain cells can most 
fitly be employed for the welfare of the individual and of society. 

It is already well known that the barbarians were able to learn foreign 
languages with greater facility than the Greeks and Romans. ^^ When we 
say of young peoples that they will some day excel us in literature, as in 
art and in science, we, unconsciously perhaps, intimate thereby that their 
brain still possesses tracts of virgin soil, which, with later cultivation, 
will become fertile. 

VI. 

The more mobile the extremities of an animal are, the more in- 
telligent it is. Among all birds the parrot is the most intelligent, because 
it makes more use than do other birds of its legs, beak, and tongue. 
The elephant is more intelligent than all other wild animals, because 
he makes use not only of his legs, but also of his snout, as organs of 
movement. 

Another consideration : The most mobile parts of the body are at the 
same time the most sensitive, e.g. the tongue, the hand, the snout. This 
increased sensitiveness depends neither on a more numerous ramification 
of nerves, nor on the more complicated character of the end organs, but 
arises from the fact that the brain itself is more irritable, as shown by 
the passions of animals, which are more violent the more mobile the 
creature is. 

Romanes ^* has already said that the higher intelligence of monkeys and 
the highest intelligence of man are related to a more perfect instrument 
of motion, viz. the hand, in which the ideal of perfection seems to have 
been reached. 

The cephalopods, which have eight arms, formed of muscle-substance 
and provided with suckers, stand, among the molluscs, nearest to the 
vertebrates on account of their strength and power of movement. It was 
movement, probably, that developed their brain-ganglia, for these are 
larger in the cephalopods than in the other molluscs. As they possess a 
good memory and a high intelligence, so they also exhibit more intense 



Psychic Processes. 391 

emotions, as may be seen from the great facility with which the color of 
their skin changes. 

The mutual relation of intelligence and movement is one of the most 
constant factors in nature. The movements always change when the 
intelligence changes. We need only consider the gait of the Indians in 
order to convince ourselves of the truth of my assertion. Their walk is 
characteristic, being heavier and slower than ours. Microcephalic indi- 
viduals have an awkward gait, and an inconsiderable dexterity in the 
movement of the hands. This change in movement is still more striking 
in the case of idiots. 

In some parts of Italy and of Switzerland there are many cretins. On 
my frequent Alpine excursions, I was often able to recognize by their gait 
the degree of intelligence of persons who were near me. I have con- 
vinced myself of the fact that the first signs of cretinism can be detected 
in the heavy gait, the arched vertebral column, and the manner of moving 
the arms in walking. 

VII. 

Neither anatomy nor physiology has hitherto been able to decide 
whether like brain cells have different functions, or whether all cells 
perform the same service. 

Since neither chemically nor by the use of the strongest microscopes 
can we demonstrate differences in the nerve cells of the cerebral cortex, 
it is therefore probable that none such exist. Hence, I believe that the 
psychic functions cannot be separated from the motor, that rather the 
psychic phenomenon and that which imparts the movement impulse both 
have their seat in the same cell. How closely connected thought and 
movement, consciousness and muscular acti^dty, are, is best seen in the 
phenomena of sleep. If, shortly before going to sleep, we hold a book or 
some other object in the hand, we notice that the object falls, the muscles 
relaxing, the moment consciousness ceases. The significance of the fact 
emphasized here is not decreased by the phenomena of movement observed 
in somnambulists and individuals who have been hypnotized. It is well 
known that one can ride and walk when asleep. By practice one can 
learn to play the pianoforte without distinguishing the individual finger- 
movements. Some can play an instrument when asleep. But these are 
not voluntary, but instinctive and reflex movements. 

In a diseased arm, in which the muscles have been atrophied, the 
sensitiveness of the fingers is simultaneously improved if one seeks to 



392 Angela Mosso : 

remove the atrophied condition of the muscles by exercises in contrac- 
tion. 

When the brain has been fatigued by exclusively intellectual activity, 
the sensitiveness of the hand and direct irritability of the muscles are 
also decreased. These observations force us to the assumption that the 
intelligence, the sensitiveness, and the movement are phenomena which 
cannot be separated from each other, that their fusion and their con- 
nection belong to the conditions which permit us to comprehend the 
nature of the mind. 

Imbecile signifies weak in body, but particularly weak in mind. In 
Latin, however, in bacillum means "leaning on a staff." The ancients 
have thus understood the relations in question better than I am able to 
express them in words. 

vm. 

It is well known that an injury on a certain spot in the left temporal 
lobe of the brain carries with it the loss of speech. Forty years ago 
Broca first described a case of this kind. At the autopsy of a man who 
had lost his speech, whose right arm and leg were paralyzed, and who, 
besides, exhibited disturbances of intelligence, there was found a broad 
and deep depression of the brain substance, extending from the Sylvian 
fissure to that of Rolando. Afterward appeared the celebrated treatises 
of Broca, which form an imperishable monument in the history of cerebral 
localization. It is the merit of James to have shown that the motor 
impulse develops itself before the appearance of language in the convolu- 
tions of the left cerebral hemisphere. 

In our development gestures and other movements appear first ; then, 
later, the sounds of language. 

It is not the process of consciousness which makes our hands dex- 
terous, but perhaps the movements of the right extremities, which effect 
the higher psychic development of the left cerebral hemisphere. 

The influence of the hand upon the development of language is evi- 
dent from the fact that an aphasic patient is made to write in order that 
he may gradually regain the power of speech. 

The relation between muscular movements and conscious processes is 
so intimate that when the arms and hands of a hypnotized person are 
brought into certain positions and certain muscles by external contact 
made to contract, certain emotions are induced corresponding to those 
muscular contractions. Here, then, intellectual processes are certainly 
effected by external muscular activity. 



Psychic Processes. 393 

There is no doubt that the first human beings were dumb, and that 
men for a long time made use of gesture-language for purposes of mutual 
understanding before they discovered sound-language. The child, too, 
before it is able to speak, expresses itself by gestures. It observes the 
looks of its parents and of the persons who speak to it, in order to com- 
prehend the meaning of the words heard. Pantomime is the heightened 
expression of the involuntary movements which accompany the individual 
phases of mental activity. In the hieroglyphs of the Egyptians and in 
the representations on Greek vases we recognize the gestures and the 
involuntary movements which men made more than three thousand 

years ago. 

IX. 

Leonardo da Vinci, in his treatise on painting, had already attempted 
to describe the passions by detailing how to represent a man in a state of 
rage and despair. The first men who were able to make themselves 
intelligible to each other must also have been the most excitable, and in 
them the motor ideas must have been very active. The word and the 
language of a people, superhuman gifts, according to the ancients, are 
produced by reflex movements, gestures, and interjections. Even now 
artists stiU feel more keenly than others the intimate relation between 
muscular movements and psychic functions ; they have the gift of repre- 
senting the effects of the emotions upon bodily posture and of idealizing 
them. 

The great, picturesque mode of representation of the human body, 
which was the glory of the Renaissance, had its basis in this physiological 
law. 

A pleiad of the greatest artists, who perceived the internal power of 
the emotions, popularized the study of bodily postures by representing in 
sacred and profane creations the feelings that thrilled the soul. They 
glorified the naked body, busying themselves with showing through the 
study of bodily forms and their movements the perfection and the phi- 
losophy of art. 

We need here neither to think of the heroic figures of Michelangelo 
and their powerful musculature, nor of the pleasing, feeling, and directly 
perceived figures of Botticelli, nor yet of the sublimely sensual, passion- 
stirred figures of the Venetian school, in order to comprehend how in 
works of art the mind is revealed in muscular contractions. It suffices 
to recall the sublime figures of Perugino, the teacher of Raphael, which 



394 Aiigelo Mosso : 

compel us to admiration with their expression of the devotion, the enthu- 
siasm, and the ardor of faith. Everything here is kept calm ; in these 
figures we find nothing exciting, the expression of the face alone mirror- 
ing the mood which the artist himself felt during the production. 

In my next lecture I will speak further of the basic conditions of the 
emotions. Here, however, I will close. 

The nervous system, as you know, consists of an intimate union 
between sense-surface and muscles. Golgi and Cajal, the greatest dis- 
coverers in the structure of the nervous system, tell us now that there 
is no difference to be found in the cells of the central organs, that there 
is no evidence of a morphological distinction between motor and sensory 
cells in the brain. 

The structure of the nervous cells is the same ; the relations alone 
are different. Probably there is but one nervous substance, which is 
active for all functions. The immense number of the brain cells is 
easily explained, since the cells can relieve one another and the nervous 
activity go on uninterruptedly from one series of cells to another. The 
greatest complication lies in the life of a single brain cell. 

In this lecture I have sought to show how intimately related are 
mental processes and movements. If we desired to make a pedagogical 
application, we might say that physical education and gymnastics serve 
not only for the development of the muscles, but for that of the brain 
as well. 



1. P. riechsig. Die Leitungsbahnen im Gehirn und Kiickenmark des Mensohen. Leip- 
zig, 1896. 

2. Th. Kaes. Ueber die markhaltigen Nervenf asern in der GehirnrLnde des Menscben. 
Neurologisohes Centralblatt, 1894, p. 410. 

3. H. Ambronn und Held. Ueber experimentelle Reifung des Nervenmarks. Arch. f. 
Anat. u. Entwioklungsges. Leipzig, 1896, p. 227. 

4. A. Mosso. Periodisohe Atbmung und Luxusathmimg. Arcbiv f. Anat. u. Physiol. 

1886. 

Die Diagnostik des Pulses. Leipzig, 1879. 

Ueber den Kreislauf des Blutes im menschlichen Gehim. Leipzig, 1881. 

5. Die Ermtidung. Leipzig, 1892. 

6. W. P. Lombard. Alterations in the Strength which occur during Fatiguing Voluntary 
Muscular Work. Journal of Physiology, Vol. XIV., 1893, pp. 97-124. 

7. Lindley, E. H. A Preliminary Study of Some of the Motor Phenomena of Mental 
Effort. Amer. Journ. Psychol, Vol. VII., pp. 491-617. 

8. D. Hansemann. Ueber das Gehirn von H. v. Helmholtz. Ztschr. f. Psychol, u. 
Physiol, d. Sinnesorgane, 1899, p. 922. 



Psychic Processes. 395 

9. H. V. Helmholtz. Physiologische Optik., p. 922. 

10. Sohon und Mosso. Eine BeobachlDuug betreffend den Wettstreit der SeMelder. Arch, 
f. Ophth. , Berlin, 1874, pp. 269-277. 

11. A. Mosso. Ueber den Kreislauf des Blutes im mensohlichen Gehlrn. Leipzig, 
1881, p. 101. 

12. A. Mosso et Pellaoani. Sur les fonctions de la vessie. Arcli. ital. de Biol., Tome 
I., p. 97. 

13. Max Miiller. Vorlesungen tiber die Wissenschaft der Spraohe. Leipzig, 1866, p. 79. 

14. G. J. Romanes. L'dvolution mentale chez les animaux. Paris, 1884, p. 4. 



THE MECHANISM OF THE EMOTIONS. 

By Professor Angelo Mosso. 

I. 

To-day I may be permitted to express my own ideas about the mech- 
anism of the emotions. 

We are sometimes surprised by a sad or a joyful piece of news. We 
all know what happens in a state of fear and distress. Physiological phe- 
nomena occur that cannot be described. But when we learn suddenly 
that the news which has troubled us is false, that our fear and distress 
had no foundation, the internal disturbance does not cease, the physio- 
logical phenomena continue in the organism in spite of all efforts of the 
will to suppress them. 

The investigation of these processes has shown that the seat of the 
emotions lies in the sympathetic nervous system. 

Before we were born, and for a long time after birth, our life was 
entrusted to the activity of the sympathetic system and the reflex move- 
ments derived from the spinal cord. We need not be surprised at this, 
when we reflect how great an importance nature has attributed to the 
vegetative and generative life processes in the formation of the organism. 

In decisive moments of life, when the emotions are most violent, it is 
just the sympatlietic nervous system that comes into action. The intes- 
tines and the smooth muscular fibres contract in order to raise the press- 
ure of the blood, and to utilize the blood better for the brain and the 
muscles. 

The first observations concerning this subject were made by me more 
than twenty years ago. I was able to see that in sleep a contraction of 
the blood-vessels always takes place as soon as the sense organs and the 
skin are stimulated, even when the stimulation is so weak that the subject 
does not wake up.^ These changes, which result without our knowledge, 
form one of the most remarkable arrangements which we can observe 

396 



Emotions. 397 

among the perfections of our organization. During the interruption of 
consciousness our body does not remain helplessly exposed to the influ- 
ences of the external world, or in danger of becoming the prey of its ene- 
mies. Even in sleep a portion of the nerve centres watches over the 
operations of the external world, and prepares in good time the material 
conditions for the awaking of consciousness. If we glance back at the 
unconscious processes which we saw take place in sleep under external 
influences, we shall see that they are all coordinated in correspondence 
with a final object ; they all coincide in favoring the circulation of the 
blood in the brain, and thereby making it possible that, in case of danger, 
the organ may awake to full activity. 

I do not believe myself far from the truth in maintaining that the 
totality of the reflex movements to be observed during sleep forms a real 
defensive apparatus for the organism. 

Other investigators have since demonstrated the same thing. Two 
years later, in 1881, Dr. Pellacani and I found that even very weak sensa- 
tions caused a contraction of the bladder. ^ These facts had, in general, 
been already known, for these contractions have become proverbial in 
connection with fear and other emotional conditions ; but no one had 
previously observed that this organ reacts with such facility to all sense 
impressions that its tonicity changes in consequence of attention and incon- 
siderable psychic jDrocesses. 

II. 

The organs of the abdomen and the pelvic cavity are just as sensitive 
to the emotions as the heart. I have studied the movements of the 
abdominal organs, the stomach, and the rectum. In the smallest emotions 
movements of the intestines and stomach always occur. 

In the movements of the bladder, we must distinguish between active 
and passive, i.e. between such as are peculiar to the bladder itself, and 
such as are transferred to it from the diaphragm and from the walls of 
the abdomen. 

In order to investigate with exactness these movements of the bladder 
itself, I have carried on experiments both on the dog and on woman. I 
shall first explain the construction of the apparatus employed, and then 
give an account of the experiments performed. 

The instrument made use of was my plethysmograph, which has the 
advantage of maintaining the pressure constant and of registering the 
slightest movements of contraction and relaxation of the bladder. 



398 



Angela Mosso 



A catheter for female use (Fig. 1) A is in communication with a 
glass tube 5 C which, with a rectangular curve, sinks to the depth of 1 or 
2 cm. below the level ah of the liquid contained in the large receptacle, P. 
This descending tube must be put into a perfectly vertical position before 




Fig. 1. — Arrangement of the plethysmograph for tracing the movements of the bladder. 



every experiment, and fixed firmly in that position by the iron support 
DE. The pressure-screws at the foot of the support facilitate this nec- 
essary arrangement. A test-tube F, like those used for chemical reactions, 
with very thin walls, and suspended by two silk threads from a pulley Cr, 
is held in equilibrium by means of a piece of lead H, which has the 
same weight as the cylinder F. To this counterpoise is fixed a pen for 



Emotions. 399 

tracing on a smoked cylinder, or on the continuous roll of a Ludwig 
kymograph. 

The cylinder F is suspended in such a manner that it has the vertical 
glass tube Q in perfect correspondence to its axis and so that it can move 
up and down without touching it. 

In order to avoid the attraction of the cylinder by adhesion to the 
tube running down its axis, and the consequent development of resistance, 
it is advisable to furnish the lower end of the tube with a little ring 
of sealing-wax, or of india-rubber, cut from a tube of corresponding 
diameter. 

The cylinder F is drawn up until its bottom touches the lower end of 
the vertical tube ; the jar P, for the time being, we suppose to be full 
of water. 

The catheter A and the bladder of the animal or human being into 
which it is introduced must be on the same level ah as the liquid in the 
large vessel. The true level is easily found by placing the plethys- 
mograph and the cylinder on which the tracing is done on a strong iron 
table, which may be raised or lowered by means of a screw ; a photog- 
rapher's table serves the same purpose. 

The tube AIBQ and part of the cylinder P beiag filled with water, 
the catheter is introduced into the bladder, and the clip / opened. If 
a contraction of the bladder takes place, a quantity of water correspond- 
ing to the diminution of the capacity of the bladder will flow into the 
cylinder F. The cylinder F, becoming heavier through this afflux of 
water, is bound to sink into the liquid of the jar below until it has dis- 
placed a volume of liquid corresponding to the increase of water received. 
If a dilatation of the bladder takes place, a certain volume of water wiU 
flow into it, and the cylinder becoming lighter will rise to a corresponding 
height above its original level. 

Had the walls of the cylinder neither volume nor weight, and were the 
jar full of water P so wide that the immersion of the cylinder would not 
sensibly alter the level of the water contained, it is clear that the cylinder 
might rise or sink without any change taking place in the level of the 
water, either in the cylinder or in the jar P. But since the walls of a 
glass cylinder, however thin they may be, have nevertheless a certain 
weight and volume, the immersion of the cylinder in water will cause a 
loss of ' so much of its weight as would correspond to the weight of a 
cylinder precisely similar with walls of water. This diminution of weight 



400 Angela Mosso : 

at the side ^ of a system FH, which is held in equilibrium by means of 
the pulley G-, must produce a displacement. The counterpoise H, which 
has remained constant, will repair the loss in weight of the cylinder F in 
raising above the level ab a weight of water in the cylinder which will 
equal the loss in weight of the cylinder in its immersion. 

A column of water being raised in this manner above the level ab, 
there is of necessity an augmentation of pressure within the bladder cor- 
responding to the height of the column. In order to remedy this defect, 
which as a rule is not more than a column of 2 cm. of water, we fill the 
jar P with a liquid which is less dense than water, that is, with alcohol 
and water. At every contraction of the bladder a corresponding quan- 
tity of water will pass into the cylinder, and the latter will sink into the 
diluted alcohol in the jar P. As, however, the density of this liquid is 
less than that of water, the cylinder F will not only, in its descent, dis- 
place a volume of alcohol equal to that of the water which it contains, but 
will tend to sink lower, thus carrying the level of the water it contains 
below the level ab of the surrounding alcohol. 

Then, again, we have already noticed that the cylinder in plunging 
into the liquid loses gradually in weight, in accordance with the well- 
known principle of Archimedes, and that the counterpoise, which remains 
constant, seeks to repair this loss by raising the inner level of the water 
ab above the level of the surrounding alcohol, until the equilibrium is 
reestablished. 

We have, therefore, in this case two forces acting in opposition : that 
is, gravity, which tends to bring the water level below the alcohol level 
ab, and the loss in weight undergone by the cylinder F during immersion, 
which gives it an upward impetus. If these two forces are equal they 
will cancel each other and the cylinder F will be able to rise and faU to 
the extent of its entire length, the level ab of the water contained in it 
remaining meanwhile unaltered. 

In order to obtain the exact degree of density necessary to this end we 
make use of an empirical method ; that is, we prepare a mixture of water 
and absolute alcohol if the cylinder has thickish walls. The liquid will 
have the required degree of density when the cylinder is filled to the 
top with water or empty ; in other words, when the cylinder is immersed 
up to its neck in the liquid or has its base merely touched by it, the level 
ab of the water contained in it remains constant on the plane ab of the 
surrounding liquid. 



Emotions. 401 

For all these necessary operations of filling, emptying the cylinder, 
adding or taking away water from the bladder, a glass tube L graduated 
in cubic centimetres is made use of. This tube communicates by means 
of another of india-rubber closed by a clip K and of a T-tube with the 
horizontal tube BC. In order to empty the cylinder F or take water from 
the bladder, an inward breath is di-awn at the mouth of the tube N, the 
tube L meanwhile being closed with the stopper M, which has a glass 
tube running through it ; in order to add water, one need only open the 
nipper K. 

For the experiments explained in the sequel a graduated and calibrated 
cylinder which contained 30 cc. to 18 cm. length was made use of, therefore 
every centimetre measured on the ordinates of our tracings corresponds 
to a little less than 2 cc. 

Care must be taken that the pulley Gr be sensitive enough and so well 
balanced that it remains in equilibrium in every position. A description 
of the apparatus that puts the cylinder 8 in movement, its velocity being 
constant or variable as required, is here unnecessary, as it is a piece of 
clockwork with a Foucault regulator which is to be found in all labora- 
tories. 

When a certain pressure was to be exercised on the bladder in order 
to dilate it, it sufficed to raise the table on which the plethysmograph 
stood, so that the level ab was above the plane of the bladder, and to add 
water with the tube L or to lower the animal or human being. 

In order to measure exactly the pressure exercised on the bladder 
during our experiments, we made use of a water level consisting of a 
simple india-rubber tube with an inner diameter of 5 mm., 1 m. in length, 
which had at its end two pointed glass tubes about 20 cm. in length. One 
of these tubes being placed near the symphysis pubis, the other was put 
against the jar P, and the difference of level between the bladder and the 
plane ab was read on a double decimetre measure. This height is the 
pressure exercised on the bladder. 

Six days after a fistula had been applied to a male dog the bladder 
was connected through it with my plethysmograph, and the curve thus 
obtained recorded on a rotating cylinder. Simultaneously I had the tho- 
racic and the abdominal respiration registered. The movements of the 
bladder and of the abdomen are by this means directly fixed upon the 
cylinder, while the thoracic respiration is represented reversed upon it, 
i.e. a sinking of the curve corresponds in the latter case to expiration, a 
2d 



402 



Angela Mosso : 



rise to inspiration. Since the three curves were recorded exactly over 
each other, the movements could be studied independently and com- 
pared (Fig. 2). 

The curve for the bladder showed, as was to be expected, also the 
respiratory movements. In this curve we see that the bladder begins 
to contract before the abdomen rises. This comes from the fact that 
the sinking of the diaphragm depresses the intestines, and, with them, 
also the bladder. The eifect must first appear in the very place where 
the resistance is least, i.e. in the open bladder ; then the abdominal walls 




Fig. 2. — Relation between the respiratory movement of tlie thorax (line T) and of the 
abdomen (line A) with the passive movements of the bladder (line B) . 



are forced forward. Some time after the contraction of the diaphragm 
the expansion of the chest begins. 

But, besides these respiratory movements, there can be perceived in 
the bladder curve a slight sinking, and, after it, again a rising of the 
whole curve. These are active movements proper to the bladder itself. 
They are easily distinguished from the passive movements, since they 
occur less quickly. 

Another day while we were recording the movements of the bladder, 
a servant, to whom the dog was much attached, entered the laboratory. 
Immediately the curve showed an active contraction of the bladder, as 
may be seen in Fig. 3 at (r. In aba we see passive movements of the 



Emotions. 



403 



bladder, which have become weaker because the respiration is 
more superficial. 

When, shortly before, another person, whom the dog did 
not know so well, had entered the room, we had also noticed 
another, but stronger, contraction of the bladder. In order 
to keep the dog quiet, one of us laid his hand on his head. 
(See P in the curve of Fig. 3.) When the hand was taken 
away, and the servant laid his upon the dog, there occurred 
again an active, but less marked, contraction of the bladder. 
As soon as the respiration became more superficial, the passive 
movements of the bladder became also less distinct. 

After these observations, the dog lay with eyes half -closed, 
as if he was about to go to sleep. His tail was touched, and 
immediately afterward the curve showed an active contrac- 
tion of the bladder, while — what is noteworthy — the rhythm 
and depth of the respiratory movements did not change. 
After the bladder had again assumed its full volume, and 
while the dog was perfectly quiet, his skin was touched, and 
the curve record showed at once a stronger, active contraction 
of the bladder. In like manner, sensations of pain, which we 
produced by pulling the dog's ears, caused strong, active con- 
tractions of the bladder. 

Such experiments were many times repeated. They were 
also carried on with bitches, the bladder being directly con- 
nected with the plethysmograph by the introduction of a cathe- 
ter, without previous establishment of a fistula. The results 
which we obtained were always the same. It was sufficient 
to speak kindly to the animals, or to caress them, to make the 
curve express the psychic influence upon their active move- 
ments. 

But I could not rest content with these results obtained 
from animals. I needed to corroborate them by experiments 
on human beings. Naturally this can be done better with 
woman, since with her the bladder can be easily brought into 
connection with the plethysmograph by the introduction of a 
catheter. My clinical colleagues were kind enough to place 
at my disposal some girls from the hospitals, who readily 
offered themselves for the purposes of these experiments. 



404 



Angela Mosso : 



I may be permitted to give an account of these experiments also. 

These experiments were carried on, otherwise, as the first. Again I 
had the thoracic and abdominal respiration and the move- 
ments of the bladder independently recorded. The subject 
lay comfortably on a bed. Here, in a state of complete 
rest, the whole curve of the bladder was, at times, horizon- 
tal, showing, at others, slight active undulations. To 
touch the hand of the subject lightly sufficed, however, to 
produce at once an active contraction of the bladder. 
(See Tin the curve of Fig. 4.) 

While the subject was lying quietly on the bed, the 
clockwork of the kymograph was wound up (see (T). The 
noise resulting was entirely unknown to the subject, but 
the impression sufficed to cause itself to be reflected in 
the bladder, and to induce a contraction, visible in the 
curve. When the subject was addressed (see i'), it could 
be seen that the bladder contracted immediately, while, if 
she herself spoke (see jB), a series of such contractions 
took place. All these contractions are movements proper 
to the bladder. As was shown by other experiments as 
well, they were not transferred to the bladder from the 
abdominal walls or from the diaphragm, and were not, 
therefore, passive movements F. The lower line T marks 
the seconds. 

I was particularly interested in the movements pro- 
duced in the bladder by purely psychic influences. These 
are shown, e.g., by the following experiment. While the 
girl lay quietly on the bed, and respiration was quiet and 
normal, — this is always shown by the curves, — some one 
said to her, "Now I'm going to pinch you," but without 
doing so. Immediately the bladder contracted, without 
the slightest change being noticed in the thoracic and 
abdominal respiration. After rest had been again restored, 
a jest was spoken to the girl, and again we perceived a 
contraction of the bladder on the curve, without seeing any 
modification whatever of the two respiratory curves. 

Beyond all doubt, then, the contractions of the bladder which we 
observed were movements proper to that organ itself. 



Emotions. 



405 



All these phenomena may be considered the most delicate reflex move- 
ments which occur in the organism. I was particularly interested to know 
what influence a direct activity of the brain would exercise 
upon the movements of the bladder, and I carried on experi- 
ments to that end. The subject had only a slight education; 
she was especially a bad mental arithmetician, very easy 
problems in arithmetic causing her difficulties. She needed, 
therefore, in such work to exert her brain very much. 

While she lay quietly on the bed and her respiration was 
quite normal, she was given the following example in arith- 
metic : " How many eggs are seven dozen ? " Immediately 
the bladder was seen to contract (Fig. 5). After this prob- 
lem was solved (see TT), we had her multiply in her head 
thirteen by twelve, and then a relaxation of the bladder was 
to be seen. 

I noticed, also, that merely speaking to the girl, without 
her answering, was sufficient to produce a contraction of the 
bladder. 

m. 

The preponderating activity of the sympathetic system 
in the emotions is so great that the brain effort is not able 
to suppress it. Many men feel a contraction in the abdomen 
when they look down from a tower or other high place. 
These troublesome sensations, which are connected with the 
idea of a possible fall, are simply caused by the contraction 
of the bladder and the intestines. 

When we investigate, by means of the plethysmograph, 
the movements of the intestines during emotional states, we 
obtain the same curves as we receive from the movements 
of the blood-vessels of the extremities or of the brain, or 
from the movements of the bladder. All these facts ena- 
ble us to understand the mechanism of the emotions better. 
Umotio signifies movement. We understand now that the 
constant and fundamental movements taking place in emo- 
tions are the movements of the internal organs of vegetative 
life. 

The investigations carried on in my laboratory by Dr. Kiesow have 
convinced me that in certain emotions the blood pressure increases, and 



406 Angela Mosso : 

the blood-vessels and smooth muscular fibres contract in order to prevent 
the blood from being dammed up in the abdominal cavity. 

In order to increase the circulation of the blood in the brain and muscles 
our bodily machine has to work under a higher blood pressure. This end 
could be attained only through the sympathetic system, which sends its 
fibres every where to the smooth musculature. During blushing a paling 
of the skin can be noticed before the blood-vessels expand, and the blush 
proper takes place. 

In the study of the emotions the reflex movements of the striped mus- 
culature of the face, the extremities, and the trunk are of secondary signifi- 
cance to the physiologist. They are simply accompanying phenomena 
and, just because they are more complicated, less fundamental. 

However useful the first reactions of the nervous system are, yet we 
all know that they do not suffice for the defence of the organism in 
strong emotions. The nerve substance is so irritable that a small shock 
is enough to disturb the equilibrium. I wiU not enter into detail here, 
since I have already shown in my book on " Fear," how unstable is the 
equilibrium of the nervous system, and how easily the brain and the 
sympathetic system go beyond the proper measure in their activity when 
danger threatens, and existence is at stake. 

Even a practiced observer is often unable to decide from the gestures 
and facial expression of an individual whether he is enraged or in a state 
of the greatest joy. 

To recall the expressions of two so opposite emotional conditions 
suffices to convince us that the reflex phenomena accompanying them are 
not only useless, but even injurious. Indeed, in great pain and great 
pleasure we have the same phenomena : trembling of the muscles, secre- 
tion of tears, expansion of the pupils, decrease of visual acuity, buzzing 
in the ears, oppression of the breathing, palpitation of the heart, inability 
to speak, exclamations, convulsive movements of the diaphragm, etc. All 
these phenomena are injurious. After the emotion is over we feel nervous 
fatigue, have headache, and suffer from insomnia. I am sorry to find my- 
self in this matter in disagreement with Darwin, but I cannot concede that 
the unconscious processes occurring during the emotions (at least the best 
known and most characteristic) have always a physiological purpose. 

If we compare the expressions of pleasure and satisfaction in their high- 
est degrees with those of pain, it will be seen that there is one and the same 
mechanism for both. In my book on " Fear " I have shown that it is the 



Emotions. 407 

quantity and not the quality of the excitation which disturbs the equilibrium 
of our organism. Only the processes which take place in the system of the 
great sympathetic are purposive and advantageous for the preservation of 
life. And it cannot be otherwise. The animals, whose involuntary move- 
ments preserved them from destruction in danger, won in the struggle for 
existence over others who possessed in less marked degree this capacity. 

Whatever the emotions may be, we always see that in these states the 
blood pressure increases, the heart beats become stronger, and the respira- 
tion deeper. These advantageous effects are the same in man as in ani- 
mals, when they fix the attention, are passionately excited, curious or 
jealous, or when they run at play or in pursuit of prey. 

But as soon as the emotion becomes more intense, the equilibrium of 
the organs ceases. The condition of excitability is increased and becomes 
more complicated, contractions of the muscles and changes in the sense 
organs take place, from which it results that the capacity for resistance of 
the organism is lowered. In strong emotions, as in rage and anger, we 
are overpowered by unconscious and discoordinated movements, and a 
penetrative and irresistible transformation occurs in us, as if the influ- 
ence of education had been extinguished, as if our reason had suffered an 
eclipse. We are no longer able to suppress the internal excitement, the 
voice refuses its office, and we utter a wild cry. Many persons in such 
states gnash their teeth like wild beasts, others act foolishly, like children. 

These disturbances occur not only in the reflex movements, but also 
in the conscious processes, and more even in the latter than in the former. 
Education has taught us that we must seek to master and to calm our- 
selves during this internal excitement, for in these states we lack mental 
clearness and power of judgment, and consciousness cannot again regain 
control until these discoordinated reflex movements have ceased. Even the 
ancients knew that strong emotions resembled a suddenly occurring sick- 
ness. The legend of ancient Rome idealized a king in order to represent 
war. They gave him the name Hostilius, which is derived from hostis. 
Tradition further informs us that this king erected a temple to " Pallor and 
Fear," for pallor and fear were looked upon as malevolent, destructive 
deities who must be appeased in order that the soldiers might be victorious 
in battle.^ ^ 

1. A. Mosso. Ueber deu Kreislauf des Blutes im menschlichen Gehirne. Leipzig, 1881. 

2. A. Mosso e Pellaoani. Sullefunzioni dellavescia. Mem. d. R. Aocad. dei Lincei, 1881. 

3. E. Pais. Storia di Roma. Torino, 1898. Vol. I., Parte I., p. 305. 




^^^^^ .^^^ 



HYPNOTISM AND CEREBEAL ACTIVITY. 

By Professor August Forel. 

Gentlemen : — I beg to present to you as few hypotheses as possible, 
and to put together as far as feasible merely the facts which must form 
the foundation of the present state of the doctrine of hypnotism. We 
cannot, of course, get along with no explanatory theory at all. Before 
all, we must maintain that everything that is known can be traced alto- 
gether to phenomena of brain activity. Everything that one has tried 
(and still tries) to bring over from the field of mysticism, or so-called 
occultism, has, as far as it could be controlled, turned out to be mistaken 
phenomena of brain activity. We may calmly leave the rest to metaphysi- 
cal speculators and to the famous breadth of the imaginary knowledge 
of the ignorant. Should there be anything in telepathy, for instance, 
it would not belong here ; certainly its representatives would have to 
furnish better evidence than so far exists. 

That much is yet unexplained is perfectly evident — as obvious as 
in any other domain of human knowledge. It does not follow, how- 
ever, that facts should be ignored, even if their connections present many 
obscurities ; nor can we respect here the famous dogmatic line of division 
between psychology and cerebral physiology with the traditional awe, 
and for this I beg to excuse myself at the outset. 

Anatomical Foundation. 

However difficult it may be to this day to grasp even the rudiments 
of the relation of the brain as an organ to the physiological and psycho- 
logical aspect of its function, we should not cease one moment to work on 
this problem. Nearer and nearer we must get to it, and, truly, what has 
already been reached stands inspection well and need not cause us, in the 
least, to despair. 

We know to-day that there is only one kind of nervous elements, 
409 



410 August For el: 

that is, the neurone, the cell with its fibre and branched processes. When, 
in 1886-87, about the same time as His, I first put forth this view as 
a probable hypothesis on the ground of numerous facts, I had no idea 
that three years later my illustrious colleague, S. Ramon y Cajal, would 
establish the matter histologically in such a beautiful and conclusive 
manner. The nerve elements do not anastomose, as was formerly be- 
lieved, but touch one another by ramifying branches, end-baskets, arbor- 
izations, etc. Every nerve fibre (axone), together with its ramifications, 
is merely a part of the protoplasm of a certain cell. Further, Schiller 
showed in my laboratory that the number of nerve elements in the new- 
born (oculomotor nerve of the cat) was approximately as large as in 
the adult, and that only the caliber of the medullary fibres differed 
enormously. Since it appears certain that, in a lifetime, destroyed ele- 
ments of the central nervous system are never replaced by newly formed 
ones, we may draw the conclusion that the nerve elements of an old 
person are the same as those of his childhood, a point very important 
for the theory of memory. 

A matter of further importance is the relation of chromatic 
reaction of the nerve cell, established by Nissl, to the details of its 
finer structure. The fibrils, already recognized by v. Kupffer, Schultze, 
Leydig, and others, and the chromatic bodies present, as it were, ele- 
ments of a second order, which increase considerably the complication 
of nerve structure and open new perspectives. The same holds for the 
change of cell structure after exhausting activity, demonstrated first by 
Dr. Hodge of this University, and for the grave changes due to the 
use of alcoholic beverages established by many investigators — an addi- 
tional reason why we should banish those abominable social and indi- 
vidual nerve poisons from human diet. 

Hand in hand with the progress mentioned, we notice the advances 
in the recognition of local structural conditions in the brain of man 
and animals, of systems of neurones, etc., especially through v. Gud- 
den's method of experimental atrophy; but also by direct anatomical 
study. The works of Dejerine and Mme. Dejerine-Klumpke, and of 
KoUiker, are encyclopaedic monuments of those researches. I mention 
further the doctrine of localization built up by Broca, Hitzig, Ferrier, 
Munk, etc., which can only lead slowly to a clear and objective under- 
standing of the whole in connection with an accurate knowledge of anat- 
omy, of pathology, and of the experimental method of v. Gudden. At 



Hypnotism. 411 

the same time, we must always guard ourselves against speculations built 
on insufficient and unsafe ground, such as the recent doctrines of 
Flechsig. While it is possible to establish, to a great extent, the func- 
tion of the peripheral nerves and their nuclei of origin by direct 
observation and experiment, and while we have also a certain direct 
access to the study of the spinal cord, we recognize the function of 
the cerebral cortex in two ways : (a) by physiological experiments and 
investigations: (6) by so-called introspective or psychological observa- 
tion and experiments. But the mutual relations of sensory stimulation 
and muscular action to the hemispheres must also be observed both 
psychologically and physiologically. If I prick some one, the subse- 
quent reflex contraction is observed by me physiologically; whereas 
the character and intensity of the pain which the person claims to feel 
can only be measured by him on the psychological side. I see and hear 
his answers physiologically only, but make out their sense psycho- 
logically only, etc. 

If we consider more accurately this continual interaction between 
psychological and physiological phenomena in the light of our knowl- 
edge of the brain, we are bound to become sure of one thing, viz. 
that there is a dark field between the subjectively accessible, psycho- 
logical, sentient, and perceptive parts of the hemisphere cortex, and 
those representing the physiologically accessible, sensory receiving sta- 
tions and the motor, or efferent, mechanisms of motion. In this dark, 
intermediate field, powerful accumulations of stimuli of an unconscious 
nature must go on, and obscure, instinctive automatic mechanisms, 
inherited from our animal ancestors, must work and influence us un- 
consciously to a great extent in the shape of impulses and feelings. 
We are driven to assume that the great ganglionic nerve centres of 
the base of the brain, corpora striata, thalami, pons, tegmentum, cere- 
bellum, must play a part utterly obscure, which perhaps might clear 
up many points, if we could penetrate more deeply. Unfortunately 
this point is still far from accessible, since the fragments furnished by 
physiology are hardly fit to be digested. 

We should not forget in this whole question what recent investiga- 
tions have demonstrated, viz. that the field of expansion of a single 
nerve element, a neurone, may be very large. Just think of a Betz- 
cell of the central convolutions, the nerve process of which reaches 
through the corona radiata, the crus, pons, and pyramid, as far as the 



412 August Forel: 

spinal cord, or of a cell of the anterior horn of the lumtar cord, 
whose process reaches muscles of the foot. Thus, neurones of varied 
significance and destination cross and interweave in a thousand ways 
in the central and in the peripheral nervous systems, in order to form 
the wonderful machinery. One sees, from this alone, how brutal and 
defective the physiological experiments in the brain must be, and how 
indefinite the physiological concept of a " centre " is. 

Physiological Remaeks. 

There is but little in the old nerve physiology that can be used 
to-day, because it rested, to a great extent, on erroneous histological 
concepts. "We must accept the well-known fundamental facts concern- 
ing stimulation, inhibition, reflexes, etc., and also the results of the 
pioneers of brain physiology, Flourens, Magendie, Vulpian, Duchenne, 
etc. We may conceive that the brain is a powerful accumulator, a kind 
of very highly complicated dynamo, in which a still enigmatical physico- 
chemical wave-like power prevails, for which I have used the expression 
"neurokyme," (the "force neurique"of the French). This force does 
not cause any motion of the masses, and consequently belongs to the type 
of molecular motion, or vibration, as is shown by its great velocity of 
conduction. Its action leaves in the cell visual changes in the form 
of material signs of exhaustion. It may be accumulated as energy by 
so-called mechanisms of inhibition, and again be discharged in definite 
channels by what Exner calls "Bahnung." In this connection, O. Vogt 
has justly insisted on the important fact that in excessive stimulation 
the effect is often suddenly stopped because a radiation of neighboring 
centres of neurones takes place, which is apt to lead away the entire 
neurokyme, if those centres are more easUy excitable. In this way it is 
in a manner possible to understand associative activity. To enter upon 
detail would lead too far ; but I beg to say, in a general way, that it is 
well known that certain functions become much easier and stronger after 
a while through practice ; whereas, in an obscure but very frequent 
manner, on the other hand, certain single impulses may leave behind 
lasting inhibitions, or stimuli, and perhaps disorders of function which 
may take a pathological character, and seriously tantalize the victim. 
Such points were used, a few years ago, by Breuer and Freud in 
Vienna, for the foundation of their doctrine of arrested emotions, which, 



Hypnotism. 413 

unfortunately, was developed into a one-sided system, although it started 
from correct facts. Thus especially violent affects are apt to leave be- 
hind all sorts of nervous disorders (convulsions, paralysis, pains, dyspep- 
sia, menstrual disorders). Breuer and Freud tried to lead the patients 
in a hypnotic condition to the causative, frequently forgotten, and fre- 
quently sexual moment of the trouble, to make them dream over that 
moment and to give, once and forever, a counter suggestion, curing the 
disorder. In many cases this works ; but by no means always. 

Before all, we must acknowledge with Isidore Steiner that the 
greatest nerve centre has the dominant position in this interaction of 
the neurokymes, owing to its greater mass. It becomes the guide and 
director of the whole, and the activity of the other centres is brought 
into subjection. Steiner proved this by a clever experiment on a fish, 
and showed that in those animals the mid-brain, and not the fore-brain, 
is the director and the soul of the animal ; consequently it is not the 
morphological homology which decides the absolute anatomical size or 
physiological strength, and hence the eminently important fact that the 
relative size of the individual part of the central nervous system is of 
great importance for the relative independence or dependence. We see 
the proof for this fact in the comparative physiology of the animal series. 
The spinal cord and ganglia are far more independent in the lizard than 
in the rabbit ; much more independent in the latter than in the dog ; and 
in the dog, much more independent than in man. In man these organs 
have become the subordinated servants of the hemispheres and totally 
dependent, although their structure is much more complicated than in 
the lizard. 

We need not wonder, therefore, if the function of these lower centres 
is governed and influenced most powerfully by the dynamics of the fore- 
brain just named, even when, as in the sympathetic, only loose connection 
exists, such as would suggest, ordinarily, a greater independence. 

How is a neurokyme, which spreads over an axone, transferred from 
one neurone to the others by the contact of dendritic ramifications? 
Duval thinks, by an amoeboid motion of the dendrites, and we read that 
lately such motions have been directly observed in transparent animals. 
This hypothesis seems, however, quite immature as yet. It does not 
explain the extreme rapidity of the conduction of the neurokyme. The 
functional play of the neurones is better explained by pure molecular 
motion, as, for instance, in electricity. It would seem that these hypoth- 



414 August Forel: 

eses are quite premature, and we must wait for actual progress in 
observations. 

Finally, we must maintain the fundamental fact of memory, conscious 
or unconscious, viz. the residual of a dynamic trace of every nerve activ- 
ity. Such a trace always facilitates the repetition of a corresponding 
activity, even if it should be forgotten subsequently, and the entire 
activity may be called forth agaia by the effect of the stimulus merely 
associated with the first one ; for instance, ordinary remembrance. Or- 
ganic memory is independent of consciousness and is the same for motor 
as for sensory and central activities, and even for reflexes and functions 
of the sympathetic. 

Sleep and Waking State — CoNsciotrsNESs. 

Man is normally limited to two states of his brain life : sleep and 
waking condition. Physiologically considered sleep means a relative 
rest from cerebral activity with recuperation of the exhausted neurones 
by chemical synthesis, whereas in the waking state processes of oxidation 
predominate. This is certain beyond doubt, but to draw the conclusion 
that sleep is called forth by the formation of fatigue products, such as 
lactic acid, or that sleeplessness could be cured by swallowing lactic acid, 
as Preyer did, is to become a victim of fallacies. 

It does not take much acuteness of observation to see that there is a 
form of sleep which is not rest, and that the brain can rest fairly well 
even in the waking state. Further, one may sleep much and excessively 
though not exhausted, and again may keep awake in a state of cerebral 
exhaustion. Again, every unprejudiced observer must be struck with 
the usually rather sudden qualitative change in the attitude of a wak- 
ing and of a sleeping person. That sleep is readily called forth by 
certain associations, regular hours, etc., is also obvious. Finally, dreams 
give us a chance to look into the life of sleep from the psychological 
side. 

All these factors tend to present sleep as a state of qualitatively modi- 
fied cerebral activity. This is, however, only intelligible in connection 
with the concept of consciousness. 

It was a fundamental mistake of practically all physicians and most 
psychologists, to think of consciousness as a something, as a form of cere- 
bral activity, i.e. to confuse the plastic concentrative activity of our 



Hypnotism. 415 

attention witli the purified phenomenon of subjectiveness. We will not 
quarrel over words. I, for one, am satisfied to be able to rest my view on 
such a psychologist as Spencer. If any one cares to use the word 
" consciousness " in any other sense, he may do so as long as he gives us 
another word for that which I understand to be consciousness, viz. the 
phenomenon of the inner reflection of the ego, the subjective side of the 
phenomena. Slight activities of the brain, as well as violent ones, are 
reflected by it and become " conscious " ; but equally violent activities 
seem not to become conscious; they remain "unconscious." Conse- 
quently we are forced to distinguish between a conscious and an uncon- 
scious life of the brain. 

The entire discord of the phenomena rests on the peculiar facts : 
(1) that the activity of the brain does not take place in one single conti- 
nuity and connection, that, for instance, two subjective reflexes may occur 
simultaneously without being connected or " associated," so that the one 
does not know of the other and one is unconscious in reference to just 
that other reflex ; (2) that everything which is subjectively " forgotten " 
drops out of the connection of consciousness so that amnesia and uncon- 
sciousness are continually confused. 

The resulting fallacies are evident ; we always call unconscious such 
actions or states of the brain as were conscious and appear to us to be 
forgotten, or which were illuminated by a consciousness other than our 
ordinary remembered consciousness. 

In order to be concise, I venture to offer a hypothesis which agrees 
very well with all the facts : Every nerve activity is conscious, i.e. 
possesses internal reflection ; but these reflections are by no means all 
capable of remaining in a synthetical connection with one another. 
For this we need a more intense associated activity, especially where the 
connection is to be fixed by memory. Everything which appears no 
longer, or not at all, in this connection, loses the subjective connection 
with our memory ego, and we erroneously deem it unconscious, whether 
it be a past or actual activity of the hemisphere, or only one of the sym- 
pathetic or of the spinal cord. In order to express such a view consist- 
ently we must : — 

a. Eliminate the word " unconscious," and replace it by " subconscious " 
or "otherwise conscious." 

h. Accept a multiplicity of fields of consciousness, or consciousnesses, 
the contents, i.e. the illuminated cerebral activities, of which are physio- 



416 August For el: 

logically connected and influence one another subjectively, according 
to the kinds of activities underlying them ; they are only rarely, or 
partially, or never connected (associated). That subjective associations 
require higher intensity and more synthesis than the objective (physio- 
logical) ones has been shown by psychology (Hoffding). 

c. Consider all brain activity as completely independent of the accom- 
panying (subjective) illuminations by consciousness, whether it appears to 
us psychological or physiological. This is theoretically possible, at least 
for psychological phenomena. 

d. Consider the word " consciousness " as the expression of an inner 
aspect of life, not as the name for any special thing, an activity, a 
peculiarity. We use the words " energy " and " matter" in a similar way ; 
there is no energy without matter, as little as matter without energy. In 
the same way consciousness in our sense is nothing in itself, but merely 
the subjective aspect of brain life, an aspect probably common to all life. 

If we adhere to what is said, we find sleep intelligible. We observe 
the following in the condition of sleep : — 

1. The cerebral activity is highly dissociated. The ideas follow one 
another in a chaos which does not correspond any longer to the connec- 
tion of things in the actual world. Things which exclude one another in 
reality appear identical, and the reverse. My friend may be at once a 
dog, water, or a piece of wood. I may be simultaneously dead and mar- 
ried, or simultaneously in Europe and America, or see my head before me 
at a distance of twenty yards. If you study this dissociation more closely, 
you readily see that it affects not only the logical sequence of higher con- 
cepts, but the very make-up, even the constituents, of perceptions. The 
notion of time and place, the single (usually subconscious) sensations con- 
stituting a perception, are frequently disjointed, and dance together a 
veritable Walpurgis dance. Again, there prevail powerful inhibitions 
which prevent all orderly association and keep us in an oppressive despair 
and impotence. The same chaos prevails in the field of emotions and of 
volitions, but here the inhibition, or, in the emotions, powerful ebullitions 
predominate. 

2. The conceptions of dream life are hallucinations. When asleep we 
no longer distinguish between perception and spontaneous conception. 
The sensory stimuli either do not become conscious at all or they are alle- 
gorized; on the other hand, all perceptions appear as actual happenings. 
Moreover, the concept of a motion is usually not capable of eliciting the 



Hypnotism. 417 

corresponding actual muscular contraction. It is merely represented by 
a motor hallucination. 

3. Since there are no corrective concepts, some emotions and ideas 
may, in this condition, obtain an enormous power, overcome obstacles 
unsurmountable in the waking condition, and hence produce especially 
intense consequences. Just think of the evil after-effects of dreams, of 
nocturnal pollutions, etc. 

Duval has lately ventured to make a new hypothesis of sleep. He 
believes that all the terminations of the neurones are in active contact 
during the waking state by some kind of amoeboid activity. During 
sleep he thinks they simply withdraw, so that the contact ceases. What 
a beautiful and simple explanation for all the dissociations and elimina- 
tions of all the senses! For the time being this view is a mere hypothesis. 
Nothing demonstrates so thoroughly the deficiencies of Weber's and 
Fechner's psycho-physical law as sleep. There are too many intermediate 
forces between the "subject " and the measurable external stimuli. Heer- 
wagen, for instance, tried to measure the intensity of sleep by the inten- 
sity of a noise necessary to wake the sleeping person ! These two quan- 
tities are practically without any connection. Everything depends on 
the kind of association. The same sleeping person can be aroused by a 
very slight unusual sound, while the greatest noise need not disturb the 
sleep. Heerwagen further tried to make statistics on dreams by asking 
people for them ; but he forgot that most dreams are forgotten, and that 
the forgetting of dreams and the " not dreaming " are two utterly differ- 
ent things. I am convinced that everybody dreams all the night through. 
I, myself, if I observe myself at all, cannot be aroused at any time of the 
night without just having dreamed. 

Finally, there are all degrees of sleep, from the lightest, best asso- 
ciated, to the deepest. The former shows all transitions to the waking 
state. The difference in the cerebral activity during the sleeping and the 
waking condition implies a corresponding difference of the contents of 
consciousness. We consequently have two alternating conscious states 
every day and every night, and our ego is quite characteristic in each. 
A good trustworthy man may become a thief, a murderer, and a licentious 
person, a courageous man may be cowardly during sleep, etc. We usually 
forget our dreams owing to the dissociation, so that our two states of 
consciousness in sleeping and waking condition show only a slight and 
fragmentary connection. Not infrequently we find somnambulists who act 



418 August For el : 

in a coordinate manner during sleep. One who did all sorts of house- 
work in her sleep was very tired after it, but did not remember anything. 
This is also the rule in the very frequent somnambulism of children. 
Out of such an orderly activity of a sleeping brain, i.e. out of the spon- 
taneous somnambulism, originates an extraordinary and especially instruc- 
tive form of double consciousness, such as has been described by McNish, 
Azam, Dessoir, and myself. 

In my case (see Zeitschrift filr Sypnotismus, 1898), a German made 
an eight months' journey to Australia and back without in the least 
remembering it. The amnesia of retrograde and antegrade character 
came on after dengue fever. Later I was able to revive the memory by 
suggestions. It was, however, impossible to establish a connected associ- 
ation between the two visits to Melbourne on his journey out and back. 
Those two Melbournes remained for him two entirely different cities. 

The Data of Hypnotism. 

At all times in the history of mankind, hypnotism has played a great 
r81e. Magicians, miracles, miraculous cures, sorcerers, the fakirs of 
India, are so many proofs of this. The principal fact was always the 
apparent and subsequently also actual power of certain persons over 
others, the ecstatic catalepsy or sleep produced by them, the asserted 
prophecies of the hypnotized, the cure of diseases, the miracles, etc. A 
magnificent instance of hypnotic influence may be found in the history of 
King Zoroaster (cf. StoU's book on this topic). In the beginning of this 
century Mesmer thought to have discovered a new natural law in those 
phenomena, a new "fluid," which he assumed to be magnetism. Espe- 
cially in living beings he called it animal magnetism. He produced hys- 
terical convulsions usually by contact of men, finally " magnetized " trees 
and did other absurd things; but also cured a number of patients. Con- 
demned by the French Academy as an obvious fraud, he came to a sad end. 
But he retained adherents. One of them, Puysegur, discovered the quiet 
hypnotic sleep. They all adhered to the belief in a mysterious magnetic 
fluid. Braid, an English physician, was the first to take a great step 
toward a scientific elucidation of the question. He found that the 
whole series of phenomena depended not on a fluidum coming from the 
outside, but on the brain and nervous system of the person influenced. 
The very title of his book, "Neurohypnology," shows this. He found that 



Hypnotism. 419 

certain stimuli and also certain ideas could produce this changed cerebral 
state, hypnotism. By this he had established the principal fact, but he 
made a mistake in the method by ascribing a capital role to the periph- 
eral stimuli, just as Charcot did later on. He hypnotized with brill- 
iant objects, and, therefore, did not obtain thoroughgoing results. 
These we owe to Liebault, at Nancy, and to his medically and philosoph- 
ically highly educated friend, Professor Bernheim. The doctrine of 
Liebault and Bernheim has placed hypnotism among the fields for scien- 
tific research, from which it will not disappear again. This doctrine 
reduces hypnotism to the concept of suggestion. In this light we shall 
mention briefly the principal manifestations. 

The fact that in falling asleep or awaking the entire mode of brain 
activity is suddenly altered, gives us, I believe, the key to an under- 
standing of hypnotism. Conceive some means by which we are able to 
produce those two kinds of activity according to our needs, and, more- 
over, to localize, — to limit them to certain fields, — and you see before 
you almost the entire series of hypnotic phenomena. For this purpose 
you should merely be able to direct the cerebral activity of your neighbor, 
inhibit and facilitate, associate and dissociate. This actually happens 
by means of evoking certain concepts, which are known to lead most 
easily to dissociation. A priori, this may appear peculiar and improbable. 
As a matter of fact, it is exceedingly simple and common. All human 
beings are naturally more or less suggestible and, therefore, hypnotizable, 
although not all are equally influenced by others. Everything that pro- 
duces the concept of sleep, everything that makes man passive, or throws 
him into ecstasy, admiration, or confidence, may be used by the rapid and 
concentrated action of the hypnotizer to dissociate, inhibit, or stimulate, 
any activity of his subject, — it may produce the desired and foretold 
effect, the mechanism of which remains subconscious in the person influ- 
enced. It is especially advantageous to begin with such effects as are 
readily obtained. This is the principle of Liebault's method. 

For instance, I yawn; it becomes "infectious." Another yawns; 
with him it has the effect of a suggestive influence. He yawns because I 
yawned ; however, he remains subconscious of the mechanism which pro- 
duces the yawning. Now, I use the beginning dissociation, and tell him 
rapidly and with assurance : " You are quite sleepy, you cannot keep your 
eyes open, you cannot open them, you have a warm feeling in your feet ; 
look at me ; you are already asleep, your arms are heavy," etc. Quite fre- 



420 August Forel : 

quently tlie subject will feel and even show the one or the other of these 
phenomena. If he is very suggestible, he will, perhaps, be asleep in a 
few seconds, to the surprise of those around. This sleep is, however, dis- 
tinguished from ordinary sleep by remaining under my direction, i.e. by 
my remaining in connection with the sleeper through his hearing. As 
soon as I have reached this point a further mastership over his cerebra- 
tion is an easy matter. I take his arm, lift it, and declare that he cannot 
lower it ; and he cannot with all his efforts. I put both hands into a 
rotating motion, and he cannot stop without my permission. I declare 
that his hand, which I touch, is not sensitive, and no prick of a needle is 
felt any longer. I give him water to drink, declaring that it is chocolate ; 
he tastes the chocolate. I tell him to open his eyes, make the dead 
appear before him, make him hear music which does not exist, assure him 
that he is a piece of wood, another person ; in short, any fantastic non- 
sense ; he feels it, believes it, lives through it. I awake him when I want 
to, put him asleep by another word in a quarter of a second, and allow 
him to either remember or forget everything that has been said or done 
to him. In short, I make his cerebration play as in a dream, but fol- 
lowing my orders, surprise himself and all the spectators, and gain with 
the public the name of an accomplished magician. The whole trick con- 
sists in getting, to start with, an easily suggestible person, readily 
passing into somnambulism. If one is shown to be hypnotized, the 
others follow like the sheep of Panurge. The case described was that of 
a person easily put into artificial somnambulism. He need not be a spon- 
taneous somnambulist for this purpose. The latter are rather rare, 
whereas fully twenty-five per cent of mankind can be thrown into arti- 
ficial somnambulism. The spontaneous somnambulism, however, usually 
represents the autohypnosis of a hysterical person. 

With others the matter is slower and more difficult, although it is 
facilitated by example (imitation). Many suggestions may at first be 
without effect ; but with patience and practice one obtains at least a par- 
tial influence in ninety-six per cent of men. The person to be hypno- 
tized must be neither insane nor in a state of emotion, of excitement, or 
fear. He must before all be treated in a friendly and quieting manner. 
Flies are caught with honey. First you must gain his confidence. Put 
him into a comfortable easy-chair, the head resting ; put the right hand on 
the forehead, tell him to look into your eye, and explain to him that you 
are going to let him fall asleep, or, at least, to influence him. According 



Hypnotism. 



421 



to Bernheim, you have him look at two fingers of the left hand, after a 
few seconds lower them slowly in order to make the eyelids sink and, if 
the eyes do not close by themselves, you order them to be shut. Then 
you begin with easy suggestions, and pass to more difficult ones as soon 
as the others succeed. By no means all suggestions succeed with all 
people. According to the success of the more important categories, one 
may distinguish three or four degrees of hypnotism, of course with 
numerous transitions: — 

1. Somnambulism, in which practically everything succeeds. 

2. Deep sleep, in which at least amnesia for the time of the hypnosis 
is obtained. 

3. Hypotaxia, in which the hypnotized yield to most suggestions, but 
have the subjective feeling of being awake and remember everything 
afterward. 

4. Somnolence, in which only few suggestions succeed, and in which 
the hypnotized can resist with some effort. 

There are, however, cases of deep sleep with little suggestibility and, 
again, others of simple hypotaxia with very great suggestibility, but with- 
out amnesia. Moreover, the hypnotizer can at any time transfer a 
somnambulist into one of the other degrees, according to suggestion. 

The following are a few especially interesting phenomena which suc- 
ceed chiefly in somnambulists : — 

Posthypnotic Suggestions. 
You declare that a certain phenomenon will take place after awaking, 
during the waking condition ; for instance, he will feel, do, see, or think 
some particular thing. This actually occurs as foretold in the suggestion. 

Suggestion d Scheance (to take effect at a definite time). 
You suggest the same thing for a later time ; for instance, the next 
day or a week afterward, or even later. This, too, usuaUy succeeds in 
somnambulists with a little patience and practice. 

Suggestion in the Waking Condition. 
After a little practice of the subject almost every suggestion succeeds 
nearly as well in the waking condition as during sleep or a somnolent 
state. 



422 August Ford: 

Not only laymen, but also many physicians, have imagined that 
hypnosis and wake-suggestion are totally different things. Nobody can 
show his ignorance of this question more thoroughly than by such a state- 
ment. Sleep, i.e. the subjective sensation of sleep of the person hypno- 
tized, is merely a generalization of the suggested dissociation in the sense 
of ordinary sleep. When this generalization becomes too broad and the 
hypnotizer leaves the subject, he may at times lose the "rapport" with 
the subject, and when he tries to give further suggestions he may fail to 
succeed or he awakes the subject, just as out of ordinary sleep. It 
requires some precaution to reestablish the connection or " rapport " with- 
out putting an end to the sleep. On the other hand, in a circumscribed 
suggestion, in a completely waking state, it is easiest to show the symp- 
tom of localized dissociation. As soon, however, as you increase the 
number of suggestions, i.e. of dissociations, in a perfectly waking condi- 
tion, you see how the looks of the hypnotized change, become more 
dreamy ; in other words, how the dissociations become more generalized 
and produce a state resembling general sleep. Beaunis and others tried 
to make out that this condition in complicated wake-suggestions and that 
of execution of post-hypnotic suggestions — practically the same thing — 
is something peculiar, a "veille somnambulique." This is quite unnec- 
essary. We are dealing merely with a more or less localized or general- 
ized condition of dissociations or sleep. It is true it differs from ordinary 
hypnosis, because in the latter a great part of brain-activity is not influ- 
enced by the hypnotizer, viz. the spontaneous impulses of the hypnotized ; 
whereas in the intentional wake-suggestions everything is governed by 
the hypnotizer. Spontaneous is, of course, not to be taken in the sense 
of undetermined free will, which does not exist. What we understand 
by " spontaneous " is merely the resultant of all actual and past plastic 
and automatic brain activities as they are inherited and developed under 
the external influences during life. 

Suggested Falsifications op Memory. 

This is one of the most surprising illusions produced by suggestion, 
described in a masterly manner by Bernheim. You suggest to some one 
that he remembers accurately to have done, experienced, seen, or heard 
something, while there is absolutely no truth in it. This succeeds 
remarkably well. If external conditions make it possible very dan- 



Hypnotism. 423 

gerous false witnesses might be produced in this way. Children espe- 
cially are surprisingly disposed to such suggestions ; also hysterical 
women, and even normal persons. For this it does not take a professional 
hypnotizer. Ordinary attorneys, and also physicians, obtain sometimes 
unknowingly such suggested confessions or symptoms. Curiously enough 
it is sufficient to suggest the chief points of the situation, and to leave 
the rest to the imagination of the subject. He completes himself every- 
thing that was missing in the suggestion given, and furnishes a mass of 
precise details, which he makes up, and believes in, and by which the 
deception is increased. Conscientious judges will, of course, find that 
the statement does not agree with the facts ; but unfortunately sufficient 
pains are not always taken. We cannot say that the witness lies; he 
speaks with the greatest conviction, and makes a deep impression on the 
audience, especially on the jury. 

Thus we see a series of phenomena, the beginning of which is insig- 
nificant, and which all occur, more or less, in normal sleep and in certain 
people, which, however, when called forth rapidly and in a condensed 
form, makes a very baffling, confusing, and almost miraculous impression. 
Especially confusing are the mass-suggestions, which take hold of a great 
number of enthusiastic believers, produce hallucinations of all senses, 
even of the tactile sense, and thus create convincing witnesses for appari- 
tions, even for "materialized" spirits. Such is indeed the great tendency 
of our brain toward illusions. Only the more thorough psychologists are 
less surprised by these phenomena, because normal psychology has led 
them already to similar concepts. 

The essential feature of suggestion is evidently the production of a 
sleeplike dissociation of brain activity by the means of ideas. Dissocia- 
tion is used to call forth inhibition, facilitations, hallucinations, reenforce- 
ment of stimuli, decisions, impulses, affects, etc. A further characteristic 
feature is that the person influenced is never really conscious of the 
mechanism of the actual realization of a suggestion. In a general way 
suggestion makes it possible to eliminate consciousness, i.e. conscious 
memory, from any phenomenon whatever, and to bring it into the circuit 
again. You may make the "skin" (or rather the parts of the brain 
connected with it) totally insensitive to pricks, and yet later make con- 
scious the sensation which was not actually present at the moment of the 
prick. Or you may produce the sensation of a prick and later make the 
subject amnesic for the pain felt, so that he will emphatically assure you 



424 August Forel: 

that he did not feel anything, although this is not true. Again, you may 
suggest the pain of a prick which never occurred. In short, a weird play 
is possible with memory, consciousness, motion, and sensation in som- 
nambulists. 

The effect of facilitating or inhibiting suggestions goes even further. 
It may involve the sympathetic, and call for, or arrest, menstrual hemor- 
rhages, and influence blushing, bleeding from the nose, peristalsis, etc. 
Constipation, as well as menorrhagia, can be cured as if by miracle ; per- 
spiration and even the pains of labor can be influenced. Surgical anaes- 
thesia is quite often easily obtained. Even blistering of the skin has 
been produced by Wetterstrand beyond doubt. 

AU these things are continually doubted, especially by our esteemed 
colleagues, the physicians, and the lona fides of the h)rpnotized is continu- 
ally denied. They cry: Mystification! Illusion! I hardly care to men- 
tion as a proof that I had several women controlled to whom I suggested 
menstruation to take place on a definite day of each month, exactly at 
7 A.M., to last three days exactly, not merely once, but after the sugges- 
tion had had its regular effect for months. After all, theoretical criti- 
cisms can always be made against all such controls. If, however, I submit 
to your consideration the fact that the many thousands who were hypno- 
tized by Liebault, Bernheim, Wetterstrand, van Renterghem, Vogt, and 
myself, almost all came in order to be cured of some disorder, and 
certainly not in order to deceive me, the objection that it might be hum- 
bug falls naturally, especially if you consider the regularity of the 
phenomena. It would be inconceivable that thousands of independent 
people, who come to a physician in order to be cured, should agree on the 
same story to deceive the physician in the same manner, and to simulate 
both hypnosis and cure. These considerations alone demonstrate the 
absurdity of the objection. Yet if I mention cases of perfectly honorable 
and loyal men and friends whom I have cured of constipation and similar 
things, if I mention a professor of surgery whom I made anaesthetic and 
again sensitive in a quarter of a second, not only in hypnosis but also in 
the waking state, such a hackneyed objection might finally be dropped. 
It is chiefly traceable to a fundamental ignorance of psychology and of the 
life of the brain on the part of the majority of physicians. Universities 
ought to put an end to this. It is, after all, by no means astonishing 
that a dynamo weighing three pounds, as the brain does, should be able 
to produce strong effects on the circulation, peristalsis, etc., by means of 



Hypnotism. 425 

the neurokyme current through the peripheral nerves and ganglia. And 
if we are obliged to admit that an affect or a dream may have grave and 
lasting psychological consequences, such as paralysis, convulsions, pains, 
etc., why should not a suggestion be able to undo such consequences ? 

We cannot help admitting that, so far, we have greatly underrated 
the dynamic effects of the neurokyme in the brain, both on its evil and on 
its good side. We must go farther and declare that many diseases which 
internal medicine, gynecology, etc., have been in the habit of treating from 
a local point of view are nothing but affections of the brain which ought 
to be treated by suggestion alone. I merely speak of habitual constipa- 
tion, of sleeplessness, of chlorosis, of most dyspepsias, and of most men- 
strual disorders. And further, we must claim that a larger number of our 
so-called remedies, such as electro-therapeutics, balneotherapy, many 
prescriptions, etc., cure merely by suggestion, and by no means through 
some imaginary specific action. The irregularity of their results, indica- 
tions, and application prove this sufficiently. It must be admitted that 
such a remedy gives, in many cases, a stronger suggestion than mere 
verbal suggestion. In America, we ought not to forget the famous 
Keeley Gold Cure for inebriates, as a beautiful instance. Since Keeley 
suggested total abstinence, he was bound to have lasting results. 

Let us not forget that therapeutic results of suggestion are nothing 
but lasting post-hypnotic effects, which, however, like everything normal, 
have a tendency to become lasting. We do not put anything new into 
the body ; we merely lead the nerve paths back to the normal dynamic 
course. 

It is rarely possible to hypnotize a person against his will, because 
confidence is the first condition of success. As soon as the hypnotized 
loses confidence in the hypnotizer, the influence of the latter is usually 
over. The brain does not submit any longer to voluntary dissociation, 
but it associates and concentrates all its energy against the lightly built 
dynamic structure. 

There remain a few special points : — 

Autosuggestion. — By this we mean suggestions which arise spontane- 
ously, or at least without intention. 

Hypnosis and Hysteria. — It was a serious blunder of Charcot, and 
especially of his pupils, to mistake hypnotism for hysteria, i.e. a normal 
fundamental quality of the human brain for a pathological condition. It 
was, therefore, inevitable that the Paris school of hypnotism had to yield 



426 August Forel: 

to that of Nancy. Bernheim showed quite correctly that the so-called 
great hypnosis of Charcot, with its suj^posed three phases appearing on 
definite stimuli, was nothing but an artefact by suggestion in pathological 
hysterical subjects. 

Nevertheless, hysteria deserves special mention here, because its funda- 
mental symptom consists precisely in a pathological exaggeration and degenera- 
tion of dissociability or autosuggestihility. The hysterical, men and women, 
are, moreover, known to be much predisposed to convulsions, so that the 
hysterical react peculiarly to hypnosis. They are, as a rule, very sensitive 
to all hypnotic procedures, but exceedingly difficult to direct. They add 
to every suggestion a mass of autosuggestions, begin to get convulsions 
or headaches, or all sorts of other disorders which their brain adds on 
account of its oversensitiveness and excessive dissociability. So it easily 
happens that for one pathological symptom removed by suggestion, auto- 
suggestion favors one with three new ones. Hence, hypnosis is an 
excellent, though double-edged, reagent for testing a hysterical subject. 
As a rule, however, it will be possible to see after one attempt how an un- 
obtrusive and well-calculated suggestion may suffice in a conversation with- 
out the title " hypnosis," and ui a perfect waking state. An awkward 
hypnotizer, or one ignorant of hysteria, wiU usually do harm to the 
hysterical, produce hysterical attacks, etc. The hysterical are apt to 
pass into deep cataleptic, and even lethargic, conditions from which they 
are difficult to rouse. In short, to play on them with hypnotism is play- 
ing with fire. AU the unintentional damage which is attributed to 
hypnotism concerns hysterical subjects. I therefore tell every physician 
who wants to hypnotize : " Beware especially of the hysterical, and do 
not run any risk before you sit well in the saddle." Suggestion can do 
much good in the hysterical, but the physician must proceed exceedingly 
cautiously, individualizing, without even mentioning the word hypnotism. 

Crime and Hypnosis. 

This chapter was exaggerated to the extreme by Li^geois, and dealt 
with too lightly by Delboeuf . That misuse, especially sexual misuse, of 
hypnotized persons, may occur once in a while, is certain and possible, 
especially in deep hypnosis, in hysterical lethargy, etc. Even more 
dangerous is, however, the blackmailing by hysterical impostors. Hence 
the rule : Never hypnotize a woman alone, without a witness. That the 



Hypnotism. 427 

hypnotized might be used for crime is theoretically possible and experi- 
mentally proved. But no such case has really occurred yet. False testi- 
mony through suggested falsifications of memory is about the most serious 
possibility. Abnormal love-affairs of pathological persons, especially of 
the hysterical or of pathological impostors, in which hypnotism plays a 
r61e (case of Czinsky, etc.) rather belong to psychiatry. Of late those 
suffering from paranoia and other forms of insanity show a predilection 
for the delusion that they are secretly hypnotized. 

Crimes through hypnosis are probably so rare because, as is said above, 
confidence is the first condition of hypnosis. 

The insane can usually not be hypnotized, because the instrumental 
dynamo, the brain, fails to work properly, attention is defective, etc. 

One can hypnotize only in one's mother tongue, or in another lan- 
guage which one knows very well, for it takes, before all, great certainty 
and rapidity, and a blunder in a foreign language which makes it difficult 
to understand, disturbs the " rapport " considerably. 

For the purpose of watching patients dangerous to themselves, I have 
hypnotized the watching nurses with great success, and in this way pro- 
duced a " sleeping night watch," who watches much better than a waking 
person, and does not become exhausted or overtired. I hear that my 
successor at Ziirich, Professor Bleuler, continues the matter with equally 
good success. I give the nurse the suggestion to sleep quite well, but to 
notice during his sleep every unusual action of the patient, so that he 
awakes at once when the patient makes an attempt at suicide, and at once 
falls asleep again when the danger is averted. In artificial somnambulism 
this succeeds remarkably well. 

Thebapy of Nervous Diseases by Work. 

Creneral Psychotherapy. 

Starting from the experience that agricultural occupation is the best 
for the insane, and that the natural man does not work as one-sidedly as 
the " civilized," but always has, as the condition of getting along, depended 
on a combination of mental occupation with muscular activity, I have tried 
for a number of years to treat severe cases of so-called nervous diseases 
(neurasthenia, etc.), i.e. psychopathias, with such occupations. A severe 
case which I thus cured by agricultural work encouraged me. Mr. 
Grohmann, a civil engineer, himself a patient, had recovered his health by 



428 August For el: 

gardening, and was much interested in the matter. I encouraged him in 
his attempt to occupy nervous patients in his gardens. This was the 
beginning of his institution for the occupation of nervous cases, which 
increased from year to year. Carpentry was added among other occupa- 
tions, and very good results were obtained in severe cases. P. J. Moebius 
later gave the method much support, and the data were published in the 
dissertation of Menier (Ziirich), and later more fully by Grohmann him- 
self. 

Grohmann emphasizes the observation that a combination of his treat- 
ment with suggestions by Dr. Ringier in Ziirich led very frequently to 
good results. 

My principal idea in the matter was that not the muscular labor as 
such, but especially the centrifugal concentration of attention on deter- 
mined muscular innervation for an occupation, mentally satisfying and 
with a purpose, diverts the brain from pathological activities, and acts as 
a cure. Stupid muscular labor, as gymnastics, dumb-bells, and turning of 
the ergostat, does not give any satisfaction, and, above all, does not keep 
the mind or attention from going astray. Moreover, such useless activi- 
ties cannot be pursued for any length of time as a real pursuit. 

Now I should like to go a step farther to-day, and to sketch with a 
few cases a partially new chapter of psychotherapy, not touched upon by 
me so far. 

Not all neuropaths are fit patients for horticultural, agricultural, 
or other work, nor is the pathology of brain life done justice to merely 
by the ordinary suggestions of sound sleep, appetite, and like functions. 
You further know that genius and insanity are somewhat related. 
Whereas, however, it is well known that many a genius perished with 
insanity, it is perhaps less clear to many physicians that under the picture 
of hysteria or other psychopathias, many a genius, or at least many a 
talent, may slumber and fret like a bird in a cage, and also that the thera- 
peutic cant of neurologists paralyzes the wings of the bird instead of 
liberating them. Here, if anywhere, a correct diagnosis and individualiz- 
ing treatment is necessary. To be sure, not everybody who feels himself 
to be a genius is a genius. The experience of the alienist must find out 
of the hundreds of defective brains suffering from exaltation and mental 
weakness, the few which are not really defective, but contain a wealth 
of high talent, the development of which is inhibited or jmralyzed by 
certain disorders. If, however, you have discovered such a hidden, tied- 



Hypnotism. 429 

down treasure among the numerous nervous patients (brain-patients or 
encephalopaths), it is your grand duty to leave the path of cant, 
and to restore the wings to the eagle. Hypnosis and occupation with 
manual labor may be a very helpful accessory remedy ; but they are not 
the chief thing. It is necessary to gain the full confidence of the patient 
by affection and by penetrating into all the sides of his mental life, to 
make every fibre of his emotional life vibrate. Let the patient tell you 
the story of his entire life, live it over again with him, and allow yourself 
to be thoroughly penetrated by his feelings. In this you should, of 
course, never forget the sexual feeling which varies so strongly from one 
case to another. But it should not be examined after the ordinary medi- 
cal routine, which usually considers only the seminal emissions and the 
coitus ; but with full consideration of all the loftier vibrations connected 
with the sexual life. This being done, you search for the real definitive 
aim in the life of the patient, and lead him with determination and con- 
fidence. It is a cause of much surprise to see all the psyohopathologi- 
cal disorders disappear as if by witchcraft, and to watch how the unhappy, 
incapable, nervous wreck becomes an energetic, efficient person, who 
may amaze others by his working capacity, and remains a warm friend 
to the physician who understood him. A miserable person becomes 
happy; a "failure," a "talent" or even a "genius"; a patient, a healthy 
being. 

Allow me to give briefly a few instances. My friends may recog- 
nize themselves, but will pardon this publication in the interest of 
mankind. 

1. A highly educated young lady, the daughter of a talented father 
and a very nervous mother, had the reputation of being less endowed 
than her sisters, was nervous, and became more and more hysterical. She 
finally developed very marked paralysis, and was brought to the hospital 
for the insane. At first she was almost completely cured by ordinary 
hypnosis ; but after a number of months she had a relapse, with almost 
total inability to walk. She was again cured by continual agricultural 
work with farmers. But she felt unhappy over not having an aim in 
life. Not without hesitation I allowed her to yield to her anxious desire 
to become a nurse ; her parents were much afraid of the night service. 
But the latter was endured without trouble with the help of a few sugges- 
tions regarding it. She took up her work enthusiastically, carried it out 
with all its trials and fatigues, and became more and more active in every 



430 August Forel: 

direction, and to-day she is one of the most active members of a com- 
mittee of philanthropic ladies, doing remarkable work. 

2. A physician suffered for some time with "severe neurasthenic 
disorders," and tried in vain to cure himself with all sorts of remedies. 
He came to me with his complaints. I encouraged him, advised him not 
to consider all those disorders, and insisted on the higher ideals of his 
life. We agreed on a definite plan and he left. Later he wrote me that 
by that one conversation he had been cured. 

3. A young man with some hereditary taint, from a very religious 
family, very talented, became " neurasthenic " and nearly insane. He 
attempted suicide, and was taken to various sanitariums with complete 
interruption of his studies and very gloomy prognosis. He was abso- 
lutely unable to work any longer, suffered from headache, sleeplessness, 
and inability to keep his attention on any mental activity. Gloomy and 
in despair, he did not show any symptoms of melancholy inhibition, etc. 
He was quite clear concerning his " psychopathia " and " absolute failure 
in life." He also had suffered from various imperative ideas and actions 
which had played him many a trick. Sexually he was perfectly calm. 
He was brought to me as a case given up. Before long the talent of the 
young man struck me. More intimate relations showed him to be in a 
totally dissatisfied state of mind. Brought up in strict orthodoxy, he 
never could believe in those religious dogmata, and therefore thought 
himself to be an outcast and lost. The forced formal training, too, with 
which he was brought up was a source of disgust to him. Life seemed 
aimless to him. First I calmed him concerning his religion, and showed 
him that one can be a happy and valuable man without any positive 
belief. Further, I showed him that learning by heart is the " mind of 
the mindless," and that a mere understanding with interest stands much 
higher. I told him not to try to learn anything further, but to merely 
read with interest what interested him, and not to care whether he kept 
it or not. In this way I revived some confidence and some pleasure in 
life. He began to read his books with interest and pleasure, instead 
of learning them with disgust. As a philosopher and freethinker he 
returned to life, became an enthusiastic abstainer and a member of the 
Independent Order of Good Templars. He helped me found new lodges. 
My patient, who at first required watching for fear of suicide, soon 
became my friend and associate in the work. The nervous symp- 
toms disappeared, one after another. Finally he made a rather long 



Hypnotism. ' 431 

journey alone in a tropical country, returning completely cured and with 
perfect self-confidence. He resumed his studies, passed his final exami- 
nation summa cum laude a few years later, was admired by all his col- 
leagues for his enormous working capacity, and gives every promise of a 
splendid career. 

4. An hysterical lady consulted me — highly talented, but psycho- 
pathic from childhood, with attacks of "grande hysteric," and greatly 
excited by her living together with her mother. Notwithstanding 
numerous opportunities, she did not want to get married for a number 
of intellectual reasons. I tried hypnosis. Deep hysterical sleep came on 
and convulsions began to show. I waked her up with much trouble, 
told her boldly the result was deep beyond expectation, that she would 
be cured in a short time, and that she had been only too deeply influ- 
enced. From that time I gave her merely wake-suggestions. In a 
few days almost all the disorders had gone, also the constipation, 
and especially the convulsions {sapienti sat!^. I explained to her that 
she was most in need of work and of a definite aim in life. She did 
not care to found a family, with some justification, but was interested 
in depraved youth. Now she started out. Instead of cures in water- 
ing places, electricity, and massage, I gave her a number of books 
on criminal anthropology and introductions to the directors of prisons, 
of asylums, of the reformatories for children, etc. She took up the 
work with enthusiasm, joined the prohibition movement and the Inde- 
pendent Order of Good Templars, visited prisoners, the insane, destitute 
children, showed great interest in everything, an equally good judgment, 
and an astonishing working capacity. She improved every day, and 
left in a few weeks for a larger city, where she wishes to continue 
her studies. 

In such cases, I should formerly have prescribed mental rest, inac- 
tivity, manual labor, or what not. My patients did not improve. In 
such cases the brain is not exhausted, as one might suppose at first sight. 
It is merely misled, and works in abnormal paths ; its natural talents 
starve, are inhibited, and the activity offered it does not agree with it, or 
certain scruples of a religious or sentimental kind paralyze its activities, 
and paths for pathological brain activity are created. This we must 
recognize and change by a bold diversion. 

But beware of believing every psychopath who poses as a mistaken 
genius and wants to study higher philosophy. There are fifty cases of 



432 August Forel : Hypnotism. 

these to one of those described above. For these, agriculture is as good 
as for imbeciles and the insane. True inhibited greatness is not wont to 
brag or to think too highly of itself. We must look after it, must seek 
it and find it. Then we can go to the root of the matter and not remain 
content with mere trivial suggestions about gardening or carpentry. 



A SKETCH OF THE BIOLOGY OF ANTS. 

By Professor August Forel. 

Together with the bees and the wasps, the real ants belong to the 
insect family of hymenoptera, whereas the termites, or white ants, belong, 
like the dragon-flies, to the neuroptera. All these insects live in social 
organizations. More than all the rest, the ants have developed social 
life most highly and variedly. This is why they deserve our special 
interest. They not only present an innumerable array of individuals, but 
also a magnificent variety of forms. Nearly 3000 species, divided into 
154 genera, are already described from the five continents, and this number 
continues growing every year. 

The social state of ants has brought about a peculiar phenomenon 
called polymorphism of the species. Just as the difference of sex in man 
and animals is generally marked by so-called correlative differences of 
organization (as, for instance, the beard in man), so we find in certain 
animals that these differences become especially pronounced (compare, 
for instance, the cock and the hen). In the ants, the difference of the 
sexes becomes so excessive that the females and the males look like dif- 
ferent animals. But that is not all. An additional differentiation takes 
place in the species, in the female germs ; a certain number develop into 
a second category of females with totally different shape of the body, 
much diminished ovaries, without wings, but with a more highly devel- 
oped brain. This specialized category of females is called the " working 
ant." In .many species, even a third specialization of the female sex has 
formed, with powerful head and strong jaws, called "soldiers." The 
females and the males are usually winged, the workers and the soldiers 
always without wings. Consequently, a family or a state of ants of any 
kind consists of three or four different forms of adult individuals. In 
rare instances, additional forms exist. Moreover, there are many species 
in which an incomplete division of the workers into two categories with 
transition forms occurs (large, medium, and small workers). To these 
2 F 433 



434 August Forel : 

we must add the young brood, which consists of eggs, the footless and 
eyeless, white and tender larvae or maggots of all sizes, according to age 
and sex ; and, finally, the antlike nymphs or chrysalides. In many 
species, the larva spins a fine silk cocoon, which is erroneously called 
the Qgg. The real ant eggs are extremely small, and look almost like a 
white powder. 

The architecture of the ant body shows several important social 
peculiarities. The real brain, independent of the sense organs, is rela- 
tively very large in the worker and the soldier, smaller in the female, and 
almost rudimentary in the male, in accordance with the fact that the male 
ant plays a pitiably transient and good-for-nothing role, notwithstanding 
its powerful eyes and strong wings. Its immense imbecUity and help- 
lessness, in contrast with the well-developed senses, are a clear expression 
of its lack of brain. The real brain, Dujardin's pediculated body, 
possesses a highly developed, small-celled cerebral cortex, especially in 
the worker. 

The ants possess a social stomach or crop. It is situated at the 
entrance to the abdomen, is very elastic (when it is overfed, the cubic 
contents of the abdomen may be ten times enlarged), and does not digest, 
since it has no glands. Its undigested contents can be vomited forth at 
any time by the ant and distributed to its fellows, or to the larvae by 
feeding from mouth to mouth. The mutual feeding is one of the vital 
conditions of the state of ants. Behind the crop lies the chewing, or 
pumping, stomach. It has four hard valves, which usually close hermetic- 
ally the digestive tract of the ant. When the ant wants to eat, it opens 
the valves and pumps some of the contents of the crop into its peculiar, 
individual stomach, which is lined with digestive glands and where diges- 
tion begins. I have demonstrated these conditions by an experiment. 
I gave some honey stained with Berlin blue to a hungry ant. After it 
had eaten very eagerly, I put it with a few equally hungry companions, 
who at once surrounded it, begging. They all were filled with blue 
droplets before long. I then dissected one after another and found that 
the first stomach, filled with the blue mass, had not at first allowed a 
trace of the blue fluid to pass into the chewing stomach and into the 
digestive stomach. Only, during the following days, the digestive 
stomach slowly became stained more and more blue. 

On the fore legs the ants have a fine, spurlike comb which they use to 
clean the rest of the body. This is very necessary in the busy workers. 



Biology of Ants. 435 

In the mouth, too, they have a comb with which they clean the combs of 
the legs, the larvae, and their companions. 

Of great importance are further the mandibula, or upper jaws, which 
are usually dentated and serve as grasping tongue, biting weapon, mortar 
spoon, carrying instrument, scissors, etc. They replace our hands, our 
weapons, our scissors and knives. In the mouth they have, further, a 
tongue for licking, with fine organs of taste. 

The most important social organs of the ant are, however, the anten- 
nae, or feelers. They contain exceedingly delicate and numerous sense- 
organs for the tactile sense and odor, terminating in hairlike structures. 
The function of these sense-organs is experimentally established. It is 
especially remarkable that this protruding and mobile olfactory organ not 
only gives the ant information on the chemical constitution of bodies, 
through contact (I called this contact-odor of the insects), but also makes 
possible an appreciation of space by olfaction, owing to position and 
motility, an ability which we, with our invaginated, rudimentary olfactory 
organs, can form no conception of. This appreciation of space is possible, 
since the different nerve endings may convey to the brain simultaneously, 
or in successive moments, the impression of the various chemical proper- 
ties (odors) of various objects or parts of objects, lying side by side. 
Numerous relations of space are perceived for this reason, and especially, 
owing to the high mobility of the feelers, not merely by contact but 
already at a certain distance, at which the differences of behind and 
before, of right and left, can readily be furnished by smell. This ability 
must produce a knowledge of space which lies between that of our tactile 
sense and that of the senses of hearing and seeing. When lately Bethe 
imagined he had discovered a "polarization" of the olfactory traces of 
the ants, he mistook and overlooked these conditions completely. More- 
over, the ants perceive odor from a distance with their antennae. It is 
experimentally established that ants recognize one another as friends or 
foes merely by the means of the feelers, as Huber supposed as early as 
1810; and that, in their migration, they are largely oriented, or guided, by 
the feelers, although the eyes, too, help considerably in the orientation out- 
side of the nest. An ant without feelers is lost, and at once excluded from 
the social life; whereas without eyes it may go on working, recognizing 
its companions from its enemies, and find its way, although with more 
difficulty, at least in the nest and in its near neighborhood. 

Lubbock has proved that ants feel the ultra violet rays of the solar 



436 August For el: 

spectrum which we do not see. With the help of complicated experi- 
ments (by varnishing the eyes, or by the application of aesculin which 
absorbs the ultra violet rays) on the known instincts of ants, I have dem- 
onstrated that they see the ultra violet rays with the eyes, not photo- 
dermatically, i.e. with the skin, as many lower animals do. The flying 
females, and especially the males, have good eyes, with very distinct 
vision ; the workers, however, see usually but poorly. 

The workers form the most important social elements of the ant com- 
munity, whereas the soldiers serve for certain special functions, and the 
females and males solely for the propagation of the species. 

The socialism of the ants is limited to the solitary state of the ant 
colony. All the individuals of one colony live up to complete solidarity, 
whereas the rest of the world — with but few exceptions — and especially 
all the other states of ants, even of the same species, are rather consist- 
ently treated as enemies. Each state builds one or more nests. In these 
the immense wealth of instinct in ants shows itself. Almost every single 
species has some peculiarity in its architecture; yea, the same species 
knows how to adapt itself to the varying conditions, and to build accord- 
ingly. Our most common European ant, occurring also in North America, 
the small dark brown Lasius niger Linne, builds in the meadows large, 
regular labyrinth-like hills of earth. In stony ground it makes its nests 
under stones ; in the woods, in rotten stumps ; in houses, in rotten frames. 
Most European and North American species mine in the earth labyrinth- 
like complexes of galleries and rooms, where they nurse their brood. 
Many build a dome of earth on it, serving, like flat stones, to take up the 
radiating heat of the sun. When the sun shines in cool weather, the 
ants carry their whole brood under the cupola or under the stone. Dur- 
ing the night, or in rain or in hot weather, everything is carried into the 
depth. The ants build with their jaws and forelegs, working up moist 
earth into little lumps, during or after a rain, and making walls with 
them. They are splendid masons and know how to use a blade of grass as 
timber or a leaf for a roof. Occasionally a little stalk is sawed with the 
teeth of the upper jaw wholly or partly bent, pulled sideways, etc. I 
recommend every friend of nature to watch this activity after a warm 
rain in a meadow. 

Other ants with strong, hard jaws mine their nest in hard wood. In 
a species living in trunks of trees (^Camponotus s. Colobopsis truncatus) a 
very narrow hole leads out. It is constantly watched by a peculiarly 



Biology of Ants. 437 

transformed soldier — its big head just fills the hole and is trimmed 
flat anteriorly, so that it closes the hole flush, like a cork. Even a 
trained eye has difficulty to find the hole stuffed in this manner. A 
closely related species lives in North America. Yet other species nest 
under the bark of trees, under stones, in rocks or cracks of walls, even in 
walls of our houses. In tropical America I found a great number of the 
species in hollow, dry sticks of the brush, also in the thorns of acacia and 
in hollow trees. The ant of our woods, Formica rufa, and its next Euro- 
pean and North American cousins cover a dome of fir needles, small 
fragments of wood, etc., which keep warm the nest, built as a hollow 
labyrinth. The gates are opened by the ants in the morning and closed 
in the evening, in excessive heat frequently the reverse. Other ants 
evidently use a resin-like secretion of the maxillary gland, and cement 
with it meal of wood, earth, plant-fibres, and similar material to form 
a sort of cardboard or pulp out of which they make wonderful nests, 
either in hollow trees, as our European Lasius fuliginosus and Liometopum 
microcephalum (and the North American Liometopum apiculatum'), or out- 
side on branches of trees or on trunks, as we have found it in many 
Central American species of Azteca and Cremastogaster. 

Finally there are ants which build nests spun between the leaves of the 
trees out of a fine, silk-like texture, as the species Polyrliachis and Oeco- 
phylla, and in Costa Rica the Oomponotus senex s. textor. According to 
the most recent observations they are said to use their larvae, which fur- 
nish the thread, and which they use with the jaws as a spinning instrument. 
Certain species (^Formica exseota in Europe and exsectoides in the AUe- 
ghanies) form powerful states or colonies, which, according to McCook, 
may consist in the AUeghanies of up to 1600 nests, which are all in friendly 
relations with one another and are able to govern a whole forest. 

How does a colony form ? Huber, McCook, Blochmann, and Lubbock 
have established the following facts : At a certain season, the mature 
young brood, the winged females and males, fly out from all the nests of 
the same species. In the air, on trees, or on the tops of hills, a wild 
mass-wedding takes place in which I was able to establish mutual, but 
especially female, polygamy. Shortly afterward the stupid males perish 
on account of inability to feed themselves. The females remove with 
their own legs the loosely attached wings and creep into the earth or into 
wood, singly or several together. They build a little room, lay a few 
eggs, and sparingly nurse the larvag, or maggots, out of their own body 



438 August Forel: 

juice (they are very stout and fat) until three or four very small workers 
have grown up. These begin to work at once and to feed and care for 
their mother or mothers, which have nothing to do after this. Tlie 
wonderful feature is that the mother or the mothers keep so many sper- 
matozoa in their seminal pocket from the one multiple copulation or 
wedding, that they remain fertile for many years and are able to lay mill- 
ions of eggs. They evidently remain as a rule the mothers of the entire 
colony as long as it exists. At least Lubbock kept alive fertilized females 
in artificial nests for eight and even eleven years, and the existence of most 
colonies of ants probably does not last much longer. It is, however, not 
impossible that once in a while, later on, a female brought home by the 
workers, or a female of their own progeny fertilized already within the 
nest, may be added to their number. Except in parasitic species, strange 
females are always killed by the workers of a colony. The mothers or 
queens are well cared for and fed by the workers. Their sole work con- 
sists in laying eggs. A court of workers constantly surrounds the fertil- 
ized female, takes charge of the eggs, etc. 

The interior life of an ant colony represents the purest anarchistic 
socialism. Each individual works for the community. Some build 
the nest ; others clean every corner of it ; yet others nurse the brood, 
feed it, clean it, and carry it, according to the temperature, into various 
parts of the dwelling. Others, again, leave the nest and see to the food 
supply of the community by filling first their social crop, or first stomach. 
The workers serve one another attentively, feed, clean, and carry one 
another, and have a mutual understanding by means of the feelers 
and certain butts. The understanding, as well as the motor impulse, of 
that language of signs, evidently depends on inherited instincts, and 
is decidedly quite limited, but must be sufficient for the social require- 
ments. The males, and usually also the females, are inactive, and are, the 
former wholly, the latter largely, fed and cared for by the workers. 
Toward the outside world the whole number is usually hostile to every- 
thing living, which leads to offensive and defensive wars and expeditions, 
the study of which is uncommonly interesting for the comparative 
psychologist. 

As I said before, the workers find their way outside with the help of 
their sense of smell and of touch, and partly, also, with their eyes. But 
this is frequently very difficult for them, and they help one another in 
two ways. Individuals with especially good sense of smell (with stronger 



Biology of Ants. 439 

olfactory bulbs of the antennas) which have found something useful or 
dangerous, come home, butt impetuously against many companions, turn 
round, and are accompanied by a number of workers to the place of the 
finding or of the danger, guided by means of their sense of smell. On 
the way they often turn round to find out whether they are followed. 
Ants with relatively poorer sense of smell return home after having found 
something; take hold of a companion with the upper jaws, and induce him 
to have himself carried to the new place, motionless and partly rolled up. 
The carried, apparently motionless, ant sees and smeUs the way all the 
same, even if it amounts to thirty or forty yards. She returns to the 
nest herself and again brings new companions to the place of emigration. 
In this way, ants which have lost their way have themselves carried home 
when they meet a companion. If for any reason a colony of ants becomes 
tired of its old nest, the same course is chosen. The most enterprising 
workers search for new places, and the most fortunate and active ones 
among them finally bring the entire colony, with its brood, to the new 
site selected by them. These migrations are exceedingly instructive, 
since there are competitions between two or three new sites until one is 
victorious, because the ants come back from the others and reemigrate. 

Every working ant is capable of doing all the labors mentioned in 
turn, although many individuals, especially always the partially dimor- 
phous forms of workers, usually have their preference for the one or the 
other. Huber has shown, and I have found it corroborated several times, 
that ants completely separated recognized one another after weeks and 
months, and saluted one another as friends, merely by the help of the 
peculiar olfactory organs of the antennae. This kind of memory varies 
according to the species. 

There are immense variations in the mode of nutrition of the ants, 
and this is one of the most important causes of variety of the habits, as 
a few instances will show. 

The plant-lice are well known. On most of our plants we find these 
tiny, succulent parasites, imbibing with their trunks the juice of the 
plants, but digesting their rich and ever-present meals quite insufficiently, 
so that their excrements are a clear fluid containing sugar. It is anatomi- 
cally demonstrable that these clear droplets are not secretions of special 
glands, but really the excrements of the lice. Most ants of our regions 
are in the habit of considering the plant-lice as a kind of cattle, to look for 
them everywhere, to tickle them with their feelers until the louse passes 



440 August Forel : 

the clear drop, which is at once eagerly sipped by the ant. When no ants 
are present, the louse waits longer, and finally kicks like a horse, at the 
same time spurting forth the drop. By this the leaves get a brilliant 
coating of sugar, the so-called honey dew. In the manner described the 
ants fill their social stomach for the community. Certain species build 
a dainty mason-work of stables for the lice on the roots of the plants in 
their underground dwellings, and even take care of the eggs of the root- 
lice. Other species build stables above ground with moist earth, and 
galleries around the stalks of plants which bear leaf-lice, in order to pro- 
tect their wealth in cattle against attacks by strangers. In other regions, 
especially in the tropical countries, little larvse of cicadas and caterpillars 
of butterflies are used in a similar way as cattle for ants. The ants 
always know enough to unite their efforts, in order to lug home both 
pieces of prey and larger pieces for the construction of the nest. In 
America, Africa, and India there are ants (Dorylides) whose enormous 
colonies live as nomads above or beneath the surface. They usually nest 
for a while in the ground or in a hollow tree, whence they make enormous 
expeditions for prey, in which they attack, kill, cut to pieces, and carry 
home everything alive : cockroaches, rats, mice, spiders, etc. When they 
attack a human habitation, all the inhabitants are forced to leave at once ; 
and they are glad to do so, because within a few hours aU the vermin, 
big and small, are chopped up and carried away. Small children in the 
cradle must be protected against the intruders and taken away. But in 
return the house is free of vermin, and very soon all the ants, together 
with their prey, have disappeared. In the Dorylides the huge females 
are always devoid of wings and eyes; the males, also very large, are 
winged, however, and in possession of powerful eyes. In a short excur- 
sion through Colombia, I could watch the expeditions of the Dorylides 
species, in part at least. 

Far more remarkable even is the mode of life of the ants which 
raise fungi. They belong to the South American tribe of the Attini. 
In their frequently very large nests these animals form caves which 
reach the size of a fist. The workers climb the trees in long pro- 
cessions, every worker cuts out a spherical piece of a green leaf with 
its strong jaws, and thousands of them return laden with such leaves. 
They have three sizes of workers : big-headed giants, minute dwarfs, 
and between them a scale of medium-sized individuals. The latter are 
the leaf-cutters, whereas the giants are at the same time defenders of 



Biology of Ants. 441 

the nests and crushers of the leaves. The harvest of leaves is prepared 
into a kind of a hashed pulp, which is built up in the form of a laby- 
rinth, or rather sponge. This pulp of leaves serves as culture medium 
for the spores of the fungus (^Mhozites gongylophora MoUer), which are 
present in the nest in large quantities. The leaf-pulp rapidly becomes 
covered with a white film. The army of working dwarfs watch that 
the fungus does not fill the nest and stifle its inhabitants. Every 
growing twig or thread is at once cut off by these pigmies, hardly two 
millimetres long, until the fungus gets ready to produce its second 
form, which MoUer has called ant-kohlrabi, because they are little 
nodes resembling miniature kohlrabi. The fungus produces immense 
quantities of these kohlrabi, and the whole ant-colony lives on them. 
But the nutritive power of the pulp for the fungi is not infinite. As 
soon as a part of a sponge-like fungus garden is exhausted and becomes 
brownish, it is torn down by the ants and thrown in small brown 
grains, out of the nest, around which they form wall-like hills. In 
return, these parts are continually replaced by the fresh supplies of 
leaves. Thus they work continually, day and night, throughout the 
year, the leaf-cutters, the leaf-crushers, and the weeders of the fungus 
garden, in busy harmony, for this magnificent culture of fungi destroy- 
ing the forest. They are so numerous that they give the life of the 
virgin forests of South America a peculiar stamp. At every step you 
come across processions of leaf-carrying ants and their nests. I my- 
self was able in a short trip through Colombia to corroborate a great 
part of the beautiful and careful scientific discoveries of Professor 
MoUer, and to discover the as yet unknown gardens of fungi of several 
species and genera. Certain Attini have a rudimentary instinct of horti- 
culture, and merely use the excrements of caterpillars, wood pulp, etc. 
They raise another fungus. The final form of fungus of Bhozites is a 
large, beautiful agaric, which grows on the nests of the ants. My 
attack with spades on a nest of Atta sexdens L., one metre high and 
six metres in diameter, turned into a real battle. The Indian who 
helped me took to his heels. In a few seconds my hands bled all over 
from the sharp bites of the large warriors. But I succeeded in un- 
covering about twenty gardens in a corner of the nest. Almost every 
bite of a warrior bleeds. The natives use these animals for suturing 
wounds ; they have the ant bite together the two wound margins, and 
then they sever the body from the head. The head remains fastened with 



442 August Forel: 

the jaws, and closes the wound like a small forceps. v. Jhering has 
shown that the fertilized females of Attini carry in the mouth a piece 
of the fungus taken from the nest. In this manner they have the 
germs from which their brood raises a new garden. North America has 
a small horticultural ant, Atta ( Trachymyrmex) Tardigrada Buckley, var. 
septentrionalis McCook. 

The habits of other species of ants were well known to, and inter- 
preted by, King Solomon. I speak of the subgenus Messor, which lives 
in masses around the Mediterranean Sea. These animals also make large 
caves in the ground. They collect the seeds from all kinds of plants, 
and accumulate their subterraneous granaries. There they know how 
to prevent the sprouting until it is convenient for them. Then, in the 
moment of beginning germination, when the starch changes into dias- 
tase and sugar, they eat the grains, both in summer and in winter. 
There are no real winter provisions, as Solomon thought. 

In Texas there is an ant (^Pogonomyrmex molefaeiens) which allows just 
one kind of grass, Aristida oligantha, to grow around its nest, while all 
the other plants are weeded out. It feeds on the seeds, and is the famous 
agricultural ant of Lincecum. A closely related form (P. barhatus) 
makes peculiar pavements on the surface of its nest with little stones. 
Other ants QMyrmecocystus melliger and Mezicanus) use part of their 
workers as provision-pots. These ants are so overfed by the other 
workers that their first stomach or crop reaches the size of a wine-grape, 
and correspondingly distends the abdomen. These so-called "nurses" 
cannot walk any longer, and hang in the subterraneous spaces as pro- 
vision-pots for the community. Types of this kind live in Mexico, 
Colorado, and Texas, and are dug out and eaten by children. McCook 
has studied their habits. 

A topic worthy of admiration is the so-called symbiosis of a South 
American ant, Azteca Miilleri, with the Cecropia tree Imbanba (^Cecropia 
peltata). The tree is hollow inside. On peculiar cushions of the 
shoulders of its leaves it produces granules rich in albuminous substance 
and not present in other Cecropias (Miiller's granules). The ant lives 
in the hollow space of the Cecropia, where the mother of the colony digs 
into an apparently specially adapted, thinner portion. In this tree the 
Azteea finds a home and its food in the granules of Miiller. But it is 
very bellicose. As soon as the leaf-cutting ants, just mentioned, attack 
the Cecropia, the furious Aztecas defend the tree and throw them back. 



Biology of Ants. 443 

With what fury the Azteoa species defend their trees with the help of a 
yery odorous, resinous substance secreted by the anal glands, I have been 
able to see repeatedly in Colombia, where some live in self-made pulp- 
nests, hanging on the branches of trees, others in the Cecropias and other 
hollow trees, and one even under the flat leaves of a kind of ivy. The 
symbiosis of Azteca Mulleri with the Cecropia peltata is, however, incom- 
plete, inasmuch as a complete mutual dependence of the two organisms 
does not exist ; the Cecropia, at least, can live without the ants, at least 
in its first years. But the symbiosis of the fungus Rhozites gongylophora 
with the Atta species is complete. Neither fungus nor ant can live by 
itself ; each is absolutely dependent on the other. 

The ant nests have their parasites and domestic animals like the dwell- 
ings of man. Certain lice and worms trouble the ants, and lay their 
eggs into their brood. There also exist very wonderful relations between 
certain beetles, lepismas, centipedes, etc., and the colonies of ants. 
They are called guests, although as a rule they are rather harmful lodgers 
for the ants. They are tolerated or even loved by the ants on account of 
a certain odor or pleasant secretion of their hairs, which the ant licks 
passionately. They live as members of the colony in the ant nest, and, 
as Wasmann has so well described and Janet corroborated, take the habits 
of ants. They are fed by the ants from mouth to mouth, and even 
feed each other. They communicate by means of their feelers with 
the ants, and with one another. Even their brood is usually fed and 
raised mostly by the ants as if they were their own. Long ago I 
observed the feeding, transportation, and nursing of the larvae of Atemeles 
(a beetle living with the ants), and wondered why the ants cared for 
these strangers just as for their own brood, without, however, knowing 
then that these larvae belonged to the same beetle which is a guest of the 
ants as an adult. Wasmann has proved this ; he also has demonstrated 
the harmful influence of these guests on the ant colony which begins to 
produce pathological malformations between the worker and female, 
described by me formerly without a knowledge of the cause. 

Other guests are rather mischievous thieves, which creep into the 
nests and eat the ants or their brood (^Myrmedonia)^ or merely in order 
to eat the excrements of ants (^Binarda). The excellent biologist, Was- 
mann, knew that in migrations of a colony of ants to a new nest the 
whole gang of little guests (beetles, centipedes, epismas) know how to 
follow the ants into the nest, following the trace by their sense of smell. 



444 August Forel : 

I myself have corroborated this observation. This is, however, not the 
case with the small, round TJiorictus Foreli living in the nests of the large 
and long-legged Myrmecoeystus megalocola in Algeria. It is too small 
and too slow to be able to follow the swift ant. Consequently this beetle 
(discovered by me in Algeria, and called after me by Wasmann) always 
clings to the shaft of the feeler of the ant, and is carried in this way. A 
peculiar notch in the head-shield allows it to wholly embrace with its 
jaws the feeler of the ant without hurting it. Lately Wasmann believed 
that he found that the beetle bores a hole into the shaft of the feeler of 
the ant with its lower jaws and suck its blood. But Escherich denies 
this, and the matter is not settled. 

Even more remarkable than the relations of these guests are the 
slaves and the friendly relations of some species of ants to one another. 
Many years ago I accidentally discovered that some of our ants (for 
instance, Formica rufa, the common ant of our forests), which usually 
live by themselves and work hard, in very exceptional cases, probably 
after a war in which they were victorious, let the chrysalides of other 
weaker species (Formica fusca') hatch, rear them, and consider them as 
members of their community. This is the origin of the rare mixed 
colonies which give the explanatory history of evolution in the animal 
series for the following long-known fact. Charles Darwin had theo- 
retically surmised that mode of origin of the instinct of slavery in ants. 

The Formica sanguinea, as Huber first discovered, is almost always in 
the habit of making irregular raids in June, July, and August, in which 
they surround the nests of Formica fusca, attack this weaker species, 
and chase away after a violent struggle the inhabitants of the nest, whose 
brood they seize and carry home. The larvse and chrysalides, kidnapped 
in this manner, hatch in the nests of the sanguinea, where they feel at 
home very much as kidnapped infants. There they render the greatest 
service as workers to the robbers, so that the latter, although also rela- 
tively active, lead an easier and more insolent life of prey than their 
nearest relations. This gives the Formica sanguinea a very peculiar, 
enterprising, and intelligent biological stamp. It is taken up by the 
daily labor much less than other species. The so-called slaves, or better, 
helpers, feel themselves so well at home that they do not recognize their 
real brothers and sisters from the robbed nest, and treat them as enemies. 
It is established that the ability of ants to recognize begins only a few 
days after the hatching of the chrysalis, when the soft chitine is getting 



Biology of Ants. 445 

harder. In order to show this, I have put together larvae and new-born 
ants of various species and genera, and raised a mixed but peaceable 
colony. In North America there are families of Formica sanguinea 
(ruhicunda Emery, etc.) which have similar habits. 

The Amazon ant of Huber (Polyergus rufescens) has developed fur- 
ther the system of slaves. Their dagger-shaped, bent jaws are already 
unfit for work. Like a Macedonian phalanx, its rust-colored army, con- 
sisting of usually from 300 to 1200 ants, rushes from its nest on summer 
afternoons. In a close array and forced march it follows the path pre- 
viously reconnoitred by a few robbers, and in one half to one hour it 
covers distances of from fifty to one hundred metres. It is true the army 
often loses its way or stops until a few ants have found it again, rapidly 
butt with their heads against the others, and give them the sign to follow. 
If not, the swarm returns unsuccessfully. As a rule, however, they reach 
a nest of Formica fusca or rufibarlus, rush with an incredible haste into 
the entrances of the nest, and sack in a few minutes the entire brood of 
the unfortunate, overpowered ants in order to run home, and to throw the 
prey simply to their helpers. The observation of such an expedition is 
probably the most interesting zoological spectacle I ever have witnessed. 
I have observed them very often in the canton of Vaud, and kept statis- 
tics on the number of expeditions, of the soldiers, of the robbed nests, and 
the rapidity of the march. The Amazon ant completely depends on its 
helpers. Their entire brood is fed and cared for by them. Yea, the 
robber cannot even eat without help, and starves, as Huber and I have 
shown, in presence of the richest food, if it is not poured into its 
mouth by the helpers. It is able to swallow if its mouth happens to get 
into honey ; but the instinct to eat has been lost. The North American 
Polyergus lucidus (which robs Formica pallida falva} and hreviceps have 
the same habits. 

The little genus Strongylognathus shows how the instinct of robbing 
slaves can slowly develop into parasitism. In 1871, I discovered a new 
species in Wallis, Strongylognathus Huheri, and I was able to show on 
the spot by an experiment that it can rob like Polyergus. The more 
frequent and smaller Strongylognathus testaeeus, however, cannot do this 
any longer. This small and weak animal, in which the workers are 
dying out, according to my observations, still shows ridiculous remnants 
of the fighting tactics of its relatives. Wasmann has proved that the 
fertilized female of this ant sneaks into the nests of another kind, 



446 August For el: 

Tetramorium ccespitum, is received by the workers beside the Tetramorium 
mother, and lives beside her. For some cause the Tetramoriums raise 
from that time on the workers of their own species only ; whereas they 
allow the larvse of the males and females of their own species to perish ; 
instead of this they raise the whole brood of the Strongylognathus mother, 
perhaps merely since it causes less trouble and work. 

At last the parasitism of the Anergates atratulus goes even further, 
they having become totally devoid of workers. Here the fertilized 
female of Tetramorium ccespitum. is received; whereas the own mother 
of the colony of this species disappears in a manner not yet explained. 
As long as the existing workers live, they nurse the entire brood of the 
Anergates female, consisting merely of winged females and wingless 
males. The Tetramorium workers from that time merely work for the 
parasites. The females of Anergates are fertilized in the nest by their 
own brothers ; not till then do they fly out to found new nests. In 
this manner the species is subject to continued inbreeding, since there 
is always only one mother in a nest ; but it does not seem to suffer 
from it. In North America, Epoecus Pergandei lives as a parasite with 
Monomorium minutum. But nothing definite is known of its biology as 
yet. 

Another ant, Formieoxenus nitidulus Nyl., lives as a small but active 
tolerated guest with its entire brood in the partitions of the nests of the 
common wood ant. It also lives in the Rocky Mountains. 

The northern Tomognathus suhlcevis, however, according to Adlerz, 
penetrates as a brutal, uncalled-for guest into the nest of a weaker ant 
(^Leptothorax aaervorum}, and forces its brood on these animals, more- 
over allowing itself to be lazy and comfortable and fed by the host. 
The wingless worker of Tomognathus is at the same time female ; the 
male is winged. Tomognathus Amerioanus from Washington probably 
lives in a similar manner. 

The tinjr but warlike Solenopsis fugax lives in very small rooms and 
channels, which it burrows into the partitions of the nests of larger ants ; 
but it lives there as an enemy, robber, and thief, sneaking among the 
brood of the larger kind and eating it up. Since my first publication of 
this point in 1869, it has become known that this manner of living occurs 
in a large group of the Solenopsis species and related genera, such as 
-^^romyrma, certain Monomorium species, etc., which all represent, in this 
manner, small robbers hidden in the walls of the nests of larger species. 



Biology of Ants. 447 

It seems that in North America Solenopsis modera, pollux, and molesta live 
in a similar manner. In Africa and India the Carebara species live in the 
same way in the nest of Termites, also .^omyrma in Madagascar. 

In the Colombian virgin forests, I discovered in 1896 a new, previ- 
ously unknown relation of two ant-colonies, which I called parabiosis. 
A small DolicTioderus and a stdl smaller Cremastog aster, both of a deep 
black and glossy, live usually, though not always, together in the follow- 
ing manner : They inhabit the same nest, probably robbed from a species 
of Termites. The cavities and galleries are all in open connection, and 
are inhabited by the two species in a mix-up, almost inextricable to the 
human eye. This much is certain, that the two species do not mix. Each 
occupies definite rooms and galleries, and cares for its own brood only, 
notwithstanding the open communication. But there is peace, never 
war ; in common expeditions, the two species leave the nest in order to 
iind food on plants and trees, but only to the point where the final aims 
divide ; there they separate, and each species goes on to its special aim 
(the plant-lice or flowers). Thus we have a peaceable symbiosis without 
mixing and without any intimate relations. The relation of guests might 
well be called " Xenobiosis," the helpers' relation "boethobiosis." These 
expressions would be preferable not only among ants, but also for analo- 
gous relations of other animals. Wasmann's expressions (" Symphilie," 
etc.) are, however, preferable. Apart from the raids and the other con- 
ditions described, the ant colonies, even those of the same species, have 
warfare usually about the source of nutrition. We men believe our- 
selves the sovereigns of the earth. Obviously, the ants do the same in 
their little world, since the larger colony considers a certain district 
around its nest as its property. This district comprehends trees, plants, 
and the soil ; whoever enters it is attacked, and, if possible, slain. Hence 
the wars between neighboring colonies, wars which are often carried to 
the annihilation of the weaker part. A victory is accounted for by the 
number and courage of the warriors, and also by certain weapons, as 
stings, poison-sacks, hardness of body, swiftness, resinous secretions of 
the anal glands which are spurted out, certain tricks, as for instance in 
Polyergus the piercing of the brain of the enemy, in Formica exsecta the 
sawing off of the neck, or the like. The smaller kinds usually take hold 
of the legs of the larger ones, seize them this way, and finally kill them by 
the number of their pricks or bites ; whereas the big ones cut or crush the 
small with their jaws. Whole chains of combatants are formed, of which 



C_ 



448 August Forel : 

few may survive the battle. Slowly the victor gains ground, until the 
enemy either faces about or finally is surrounded in its own nest, chased 
away, or killed with its entire brood. Besides such larger wars, which 
may last days or weeks, there are innumerable skirmishes along the fron- 
tiers, especially about the possession of plant-lice. 

Yet ants do not merely murder and carry on warfare ; they also can 
make peace. This does not only happen because two exhausted colonies 
often give up fighting and avoid a certain strip of contested land, but 
also, in rare cases, by coalition and complete union. I have produced this 
experimentally by mixing rather large parts of nests of various colonies of 
Formica fusca with their inhabitants, or at least putting them close 
together in a strange place, where they were forced to build a new nest. 
Necessity and circumstances, the mutual need for food and habitation, 
reduced the warlike impulses. After usually insignificant threats, taunts, 
and weak attempts at fighting, the ants began to work together, and in 
the course of one or two days formed one harmonious colony. If, how- 
ever, you bring part of a colony near the nest of another one, it is driven 
away and often annihilated. 

Once (1871) I poured the inhabitants of two colonies of very hostile 
different kinds (^Formica sanguinea and pratensis) into one bag and 
allowed them to struggle one hour, in order to put them into connection 
with an artificial glass-nest. Fighting, with the greatest excitement and 
total confusion, the ants reached the glass-nest where they carried their 
larvEe. Necessity gradually reduced the fever of the battle. The next 
day several hundred had killed one another ; the survivors began to work 
together, though defiant and threatening. A few kept up the fighting 
spirit. After five days the union was perfect. Ten days later I allowed 
them to get out on the meadow, where they built a common nest and after 
that lived in undisturbed friendship. When, however, I put a few ants 
from the original nest of the pratensis with the new allies, the new arrivals 
were kindly received by their former sisters, but fiercely attacked and 
partly killed by the sanguinea. This case is very instructive, and shows 
that the sanguinea had closed friendship with only the definite set of 
pratensis, and were quite well able to distinguish them from the, as yet, 
unknown sisters. 

The instinctive feeling of duty of the workers has been illustrated by 
me in the following manner : One meter from a nest of Formica pra- 
tensis, I placed a strong portion of a strange colony of the same kind. 



Biology of Ants. 449 

They soon began the attack, and a great battle began, lasting several 
hours and costing nearly a thousand lives on the two sides. While the 
inhabitants of the nest rushed out to the defence of their home, I poured 
honey quite close to the soldiers running into the battle. Under ordi- 
nary circumstances the honey would have become black with ants in a 
short time. But the workers passing by sipped for only one or two 
seconds, could not be tempted any longer, and rushed into the combat — 
as a rule into death — although the ants have neither criminal law nor 
court-martial. Whoever wants to be a coward or egoist may do so with- 
out any interference. But the ant cannot act or will antisocially, and 
this is the secret of their socialism. In the struggle between the individ- 
ual instincts and impulses against social ones the latter usually have the 
upper hand. There are, of course, short hesitations which are very in- 
structive to observe. 

As has been said already, the community of ants realizes the purest 
ideals of our modern anarchists. No government, no king, no laws, no 
bureaucracy, no ofScials. Nobody commands, nobody obeys. Even the 
so-called slaves are perfectly free and work voluntarily, from mere in- 
stinct. Hence, absolute freedom with absolute solidarity. When a 
worker wants to be lazy, he is cared for none the less (this is seen in the 
Amazon ant, which is totally dependent on its "slaves"). But this laziness 
does not occur at all, except with the slave-makers and the parasitic species. 
Consequently there are no 'cracies, no parties, no rebellions, no crimes; 
at least almost none (and we must remember no alcoholism either) ; at the 
most only occasional individual differences which, however, are almost 
always quite short and insignificant. ^ And yet, there is the most perfect 
order, indeed, a wonderful skill to create order by harmonious, energetic 
work in a short time, in the most difficult and confused situations possible. 
If, for instance, you demolish brutally a nest of ants, take all the inhabi- 
tants into a bag, and throw them in a completely unknown region amidst 

1 1 have described one exception in my "Fourmis de la Suisse" ; a mixed colony of 
Amazon ants suffered for lack of food, owing to prolonged drought. Then I saw how a few 
helpers (slaves), importuned for food by the Amazons, would bite their "masters," and 
finally carry them as far as possible to throw them away. The hard Amazons took it good- 
naturedly, but always returned home at once. Tired of such a Sisyphus labor, one of the 
helpers began to bite, so that an Amazon lost patience, pierced the brain of the rebellious slave, 
and thereby killed it promptly. This fact is quoted by the famous criminal anthropolo- 
gist, C. Lombroso, and has been interpreted as a case of crime among ants. This interpreta^ 
tion stands discussion, and the case is certainly instructive. 
2g 



450 August For el: 

enemies, they reconnoitre rapidly, gather the brood, find a place for a 
nest, hide the brood provisionally under leaves or in the hole of a cricket ; 
the enemies are kept away, the nest built, food, especially plant-lice, is 
sought for and found, etc. 

The wonderful and manifold social instincts of ants have called forth 
many erroneous views, and produced a sort of anthropomorphism of the 
ant's mind. There are, indeed, enough analogies and points of contact be- 
tween the society of man and of ants, — slavery, raising of cattle, horticulture, 
war, treaties, etc. These are phenomena of convergence, the complicated 
connection of which in both ant and man is brought about by the fact 
of social community of living brains. The chief difference lies in the 
inherited automatism of instinct in the ant, and the immensely individual 
plasticity of the human brain. You may ask how it is that the brain of 
an ant, only the size of a pin-head (Charles Darwin calls it the most won- 
derful atom of substance of the world), can do as complicated things as 
the human brain, which weighs two and one-half to three and one-quarter 
pounds ; but you must consider the other side of the matter, namely, the 
immense limitation of an ant as soon as it ought to do something that 
does not lie in its inherited instinct. We see the Amazon ant, which has 
such complicated ways of plundering, perish beside ample food although 
it can lick and swallow, because it has lost the instinct to eat. Every 
species has its special tricks, but only those, and it never devises anything 
else. It is true, that ants adapt themselves to new conditions to some 
extent, and better than other insects, because their brain is relatively a 
little larger ; but this is the case only in a very limited manner. In its 
whole life, an ant learns almost nothing apart from a certain knowledge 
of places, and the ability to distinguish other ants ; shortly after it comes 
forth from its chrysalis it knows almost all it will ever know, innate and 
inherited ; whereas the mammals, and even the birds, learn very much 
during their lives, have far more memories, and combine and use them. 
Hence, it follows that mental or cerebral activities which are one-sidedly 
complicated, fixed in the brain and inherited, necessitate far fewer brain 
elements than the ability to learn individually to combine, to adapt itself, 
to practise new activities, and to make them become secondarily automatic 
by practice. This ability, which may be called plastic in comparison 
with the automatism of instinct, especially distinguishes the human brain, 
although even we think and feel and act far more from inheritance than 
we believe. Still there is no actual contrast between instinct and the 



Biology of Ants. 451 

plasticity of reason. There rather are thousands of transitions, especially 
the so-called hereditary dispositions, which are, so to speak, rudimentary, 
not completely developed instincts, and which, for instance, distinguish a 
Mozart or a Koszalzki, who were able to become virtuosi and composers 
as children, from unmusical persons over whom all the teachers labor for 
years in vain. 

The animals with complicated high instincts are, therefore, by no 
means more stupid than those which have only slight instincts. All 
depend on two different modalities of brain activity which may go, side 
by side, to a varying height, without excluding one another mutually. 

As I wrote over twenty-five years ago, the community of ants teaches 
us further that the social state of man cannot be arranged after the pat- 
tern of the ants. Man has too much and too little for this. He lacks 
the sexless workers, the social first stomach, and, above all, the high social 
instinct which, without any legal compulsion, works much rather for the 
community than for itself. In return, he can receive, digest, and combine 
in his powerful brain a world of plastic concepts, which the little ant, 
with her automatic, one-sided, though extremely well-built and remarka- 
bly well-used, brain is unable to do. The highly developed human brain 
contains an unlimited number of plastic powers, capable of development, 
connected with overpoweringly strong inherited egoistic instincts and pas- 
sions of animals of prey, but capable of being influenced in manifold 
manners by selections and by individual adaptations. Man and his brain 
cannot be forced into one single collective or anarchistic dogma, because 
overwhelming impulses lead him forcibly toward a higher evolution, 
which cannot be defined beforehand. We are, of course, in a position to 
recognize, to some extent, the laws of this psychical evolution, especially 
by the help of history, of ethnology, of psychology, connected with 
anatomy and physiology of the brain, and to remove, in a negative man- 
ner at least, that which deranges and inhibits it, as the use of alcohol, of 
opium, the cult of the golden calf and of illusory gods, and other causes 
of degeneration, and to try positively to increase the number of the fittest 
germs at the expense of the unfit. But, unfortunately, the higher insight 
of man has to meet continually the obstinate narrowness of prejudice, so 
that the victory of truth is not easy. 

Notwithstanding the difference of their physical organizations and 
size from ours, with all their relatively low rank in the animal series, the 
ants, with their social biology and psychology, are an extremely valuable 



452 August Forel : Biology of Ants. 

and interesting object of comparison, both of living nature and of the 
social relations of man, and for human psychology generally. They 
prove how the eternal, divine powers of nature produce equal or similar 
phenomena in completely different ways, whether they be those of living 
beings in their various combinations, or those which are called the physico- 
chemical powers of inorganic and organic nature. Have not slavery, the 
raising of cattle, and horticulture been practised by ants long before there 
were any men on earth ? These ants very probably have acquired these 
arts in the way of natural selection, automatically, in the course of innu- 
merable generations, with the helps of inherited combinations, without 
there ever having existed an ant which could have got a perspective of 
the adequacy of the process, individually. Man, however, invents indi- 
vidually, with the help of innumerable combinations of plastic impulses, 
and he often devises, individually, things which long before had been pro- 
duced by natural powers, or living beings before him. Let me mention 
the sail long used by the nautilus, electricity, etc. 

In Proverbs vi. 6-8, we read : " Go to the ant, thou sluggard ; con- 
sider her ways, and be wise ; which having no guide, overseer, or ruler, 
provideth her meat in the summer and gathereth her food in the harvest." 
To this sentence, which is scientifically true, word for word, I add the 
following : She gives man the social doctrines of work, of harmony, of 
courage, of sacrifice, and of a spirit of solidarity. 



DEGEEES CONFERRED. 



Following are the degrees conferred by the University during its first 
decade. In case of the degree of Doctor of Philosophy, the subject of 
the dissertation and the date of the examination are given. 

DOCTORS OF PHILOSOPHY. 

MATHEMATICS. 
J. W. A. Young, Sept. 16, 1892. 

On the Determination of Groups whose Order is a Power of a Prime. 
American Journal of Mathematics, April, 1893, Vol. 15, pp. 124-178. 

William H. Metzleb, Jan. 4, 1893. 

On the Roots of Matrices. 

Avierican Journal of Mathematics, Oct., 1892, Vol. 14, pp. 326-377. 

Thomas F. Holgate, May 9, 1893. 

On Certain Euled Surfaces of the Fourth Order. 

American Journal of Mathematics, Oct., 1893, Vol. 15, pp. 344-386. 

John E. Hill, June 17, 1896. 

On Quintic Surfaces. 

Mathematical Review, July, 1896, Vol. 1, pp. 1-59. 

L. Watland Dowling, June 19, 1895. 

On the Forms of Plane Quintic Curves. 

Mathematical Review, April, 1897, Vol. 1, pp. 97-119. 

Thomas F. Nichols, June 20, 1895. 

On Some Special Jacobians. 

Mathematical Review, July, 1896, Vol. ly pp. 60-80. 

Waeeen Gr. Bullaed, June 17, 1896. 

On the General Classification of Plane Quartic Curves. 
Mathematical Review, Vol. 1, pp. 193-208, 3 plates. 
Fkedeeick C. Ferry, June 15, 1898. 

Geometry of the Cubic Scroll of the First Kind. 

Archiv for Mathematik og NaturvidensTcah, B. 21, Nr. 3. 
453 



454 Degrees Conferred. 

Eknest W. Eettgeb, June 16, 1898. 

On Lie's Theory of Continuous Groups. 

American Journal of Mathematics. (In press.) 

John S. French, Marcli 28, 1899. 

On the Theory of the Pertingents to a Plane Curve. (In press.) 

PHYSICS. 
T. Pkoctor Hall, June 19, 1893. 

New Methods of Measuring the Surface-Tension of Liquids. 
Philosophical Magazine, Kov., 1893, Vol. 36, pp. 385^13. 

Clarence A. Saunders,^ July 6, 1895. 

The Velocity of Electric Waves. 

Physical Review, Sept.-Oct., 1896, Vol. 4, pp. 81-105. 

Thomas W. Edmondson, July 11, 1896. 

On the Disruptive Discharge in Air and Liquid Dielectrics. 
Physical Revieiv, Feb., 1898, Vol. 6, pp. 65-97. 

Samuel N. Taylor, July 31, 1896. 

A Comparison of the Electromotive Force of the Clark and Cadmium 
Cells. 
Physical Review, Sept.-Oct., 1898, Vol. 7, pp. 149-170. 

Albert P. Wills, June 21, 1897. 

On the Susceptibility of Diamagnetic and weakly Magnetic Substances. 
Physical Revieiv, April, 1898, Vol. 6, pp. 223-238. 

William P. Botnton, June 23, 1897. 

A Quantitative Study of the High-Frequency Induction Coil. 
Physical Review, July, 1898, Vol. 7, pp. 35-63. 

CHEMISTRY. 
Thomas H. Clark, June 13, 1892. 

The Addition-Products of Benzo- and of Toluquinone. 

American Chemical Journal, Dec, 1892, Vol. 14, pp. 553-576. 

John L. Bridge, Jan. 8, 1894. 

Ueber die Aether des Chinonoxims. (p-Nitrosophenols.) 
Liebig's Annalen, Sept., 1893, Vol. 277, pp. 79-104. 

Julius B. Weems, June 20, 1894. 

On Electrosyntheses by the Direct Union of Anions of Weak Organic 
Acids. 
American Chemical Journal, Dec, 1894, Vol. 16, pp. 569-588. 

1 Died Deo. 19, 1898. 



Degrees Conferred. 455 

BIOLOGY. 
Hekmon C. Bumpus, Sept. 29, 1891. 

The Embryology of the American Lobster. 

Journal of Morphology, Sept., 1891, Vol. 5, pp. 215-262, 6 plates. 

William M. Wheelee, May 10, 1892. 

A Contribution to Insect Embryology. 

Journal of Morphology, April, 1893, Vol. 8, pp. 1-160, 6 plates. 

Edwin 0. Jordan, May 11, 1892. 

The Habits and Development of the Newt. 

Journal of Morphology, May, 1893, Vol. 8, pp. 269-366, 5 plates. 

James R. Slonakee, June 20, 1896. 

A Comparative Study of the Area of Acute Vision in Vertebrates. 
Journal of Morphology, May, 1897, Vol. 13, pp. 445-602, 5 plates. 

Colin C. Stewaet, June 19, 1897. 

Variations in Daily Activity Produced by Alcohol and by Changes in 
Barometric Pressure and Diet, with a Description of Recording Methods. 
Journal of Physiology, January, 1898, Vol. 1, pp. 40-66. 

PSYCHOLOGY. 

Hekbeet Nichols, Sept. 29, 1891. 

The Psychology of Time, Historically and Philosophically Considered with 
Extended Experiments. 
American Journal of Psychology, Feb., 1891, Vol. 3, pp. 453-529 ; April, 
1891, Vol. 4, pp. 60-112. 

Alexander F. Chamberlain, March 9, 1892. 

The Language of the Mississaga Indians of Sktigog. A Contribution to 
the Linguistics of the Algonkian Tribes of Canada. 
MacCalla & Co., Philadelphia, 1892. 84 pp. 

William L. Bryan, Dec. 13, 1892. 

On the Development of Voluntary Motor Ability — with a Preface on the 
Requirements of Work in Experimental Psychology. 
American Journal of Psychology, Nov., 1892, Vol 5, pp. 125-204, 3 
charts. 

Frederick Tracy, May 29, 1893. 

The Psychology of Childhood. 

D. C. Heath & Co., Boston, 1893. 94 pp. 

Arthur H. Daniels, June 21, 1893. 

The New Life : A Study of Regeneration. 

American Journal of Psychology, Oct., 1893, Vol. 6, pp. 61-106. 



456 Degrees Conferred. 

John A. Bebgstrom, May 14, 1894. 

An Experimental Study of Some of the Conditions of Mental Activity. 

American Journal of Psychology, Jan., 1894, Vol. 6, pp. 247-274. 

Fletchek B. Dresslae, June 14, 1894. 

Studies in the Psychology of Touch. 

American Journal of Psychology, June, 1894, Vol. 6, pp. 313-368. 

Thaddeus L. Bolton, April 30, 1895. 

Rhythm. 

American Journal of Psychology, Jan., 1894, Vol. 6, pp. 145-238. 

Frank Drew, July 29, 1895. 

Attention : Experimental and Critical. 

American Journal of Psychology, July, 1896, Vol. 7. pp. 533-573. 

James H. Leuba, July 29, 1895. 

A Study in the Psychology of Eeligious Phenomena. 

American Journal of Psychology, April, 1896, Vol. 7, pp. 309-385. 

Colin A. Scott, June 30, 1896. 

Old Age and Death. 

American Journal of Psychology, Oct., 1896, Vol. 8, pp. 67-122. 

Ellsworth Gr. Lancaster, June 11, 1897. 

The Psychology and Pedagogy of Adolescence. 

Pedagogical Seminary, July, 1897, Vol. 5, pp. 61-128. 

Ernest H. Lindley, June 12, 1897. 

A Study of Puzzles with Special Eeference to the Psychology of Mental 
Adaptation. 
American Journal of Psychology, July, 1897, Vol. 8, pp. 431^93. 

A. Caswell Ellis, June 18, 1897. 

The History of the Philosophy of Education. (In press.) 

George E. Dawson, August 2, 1897. 

Psychic Rudiments and Morality. 

American Journal of Psychology. (In press.) 
Edwin D. Staebuck, August 3, 1897. 

Some Aspects of Religious Growth. 

American Journal of Psychology, Oct., 1897, Vol. 9, pp. 70-124. 

Feedeeic Buek, June 8, 1898. 

From Fundamental to Accessory in the Development of the Nervous Sys- 
tem and of Movements. 
Pedagogical Seminary, Oct., 1898, Vol. 6, pp. 5-64. 

Linus W. Kline, June 10, 1898. 

The Migratory Impulse vs. Love of Home. 

American Journal of Psychology, Oct., 1898, Vol. 10, pp. 1-81. 



Degrees Conferred. 457 

J. EiCHARD Street, June 11, 1898. 

A Genetic Study of Immortality. 

Pedagogical Seminary, Sept., 1899, Vol. 6, pp. 267-313. 

Daniel E. Phillips, June 13, 1898. 

The Teaching Instinct. 

Pedagogical Seminary, March, 1899, Vol. 6, pp. 188-245. 

Frederick W. Colegrove, June 13, 1898. 

Individual Memories. 

American Journal of Psychology, Jan., 1899, Vol. 10, pp. 228-255. 

Henry S. Curtis, June 16, 1898. 

Inhibition. 

Pedagogical Seminary, Oct., 1898, Vol. 6, pp. 65-113. 

Frederick E. Bolton, Aug. 15, 1898. 

Hydro-Psychoses. 

American Journal of Psychology, Jan., 1899, Vol. 10, pp. 171-227. 

Henet H. Goddabd, June 12, 1899. 

The Effects of Mind on Body as evidenced by Faith Cures. 

American Journal of Psychology, April, 1899, Vol. 10, pp. 431-502. 

The following gentlemen have taken the examination for the doctor's 
degree, but have not yet completed all the formal requirements. 

Eugene W. Bohannon, I Cephas Guillet, 

Edmund B. Huet, | George E. Partridge, 

Charles H. Walker. 



DOCTORS OF LAWS. 

HONORIS CAUSA. 
LuDwiG Boltzmann, July 10, 1899. 

Professor of Theoretical Physics, University of Vienna. 

Santiago Eamon t Cajal, July 10, 1899. 

Professor of Histology, and Eector of the University of Madrid. 

August Foeel, July 10, 1899. 

Late Director of the Burgholzli Asylum, Switzerland. 

Angelo Mosso, July 10, 1899. 

Professor of Physiology, and Eector of the University of Turin. 

:^MiLE PicAED, July 10, 1899. 

Professor of Mathematics, University of Paris. 



TITLES OF PAPERS 

Ptjblishbd by Past and Pebsbnt Membeks op the Staff, 
Fellows, and Scholars. 



H. AUSTIN AIKINS: — 

B.A., University of Toronto, 1887 ; In- 
structor, University of Southern Cali- 
fornia, 1888 ; Graduate Student, Yale 
University, 1888-91 ; Lecturer on History 
of Philosophy, ibid., 1890-91 ; Ph.D., 
Yale University, 1891 ; Professor of Logic 
and Philosophy, Trinity College, North 
Carolina, 1891-92 ; Fellow in Psychol- 
ogy, Clark University, Oct., 1892- 
Jan., 1894 ; Professor of Philosophy, 
College for Women, Western Reserve 
University, Cleveland, O., Jan., 1894-. 

Author of : — 

The Philosophy of Hume, in extracts, with 
Introduction. (Sneath's Series of Mod- 
ern Philosophers.) Henry Holt & Co., 
N. Y., 189.3. 176 pp. 

From the Reports of the Plato Club. At- 
lantic Monthly, Sept. and Oct., 1894, 
Vol. 74, pp. 359-368 ; 470-480. 

The Daily Life of a Protozoan (with C. F. 
Hodge). Am. Jour, of Psy., Jan., 
1895, Vol. 6, pp. 524-533. 

Education of the Deaf and Dumb. Edu- 
cational Review, Oct., 1896, Vol. 12, 
pp. 236-251. 

The Field of Pedagogy. Western Reserve 
University Bulletin, April, 1897, Vol. 
3, pp. 15-21. 

R. AKIYAMA: — 

School of Science, Tokio, Japan, 1888- 
90 ; College of Pharmacy, San Fran- 
cisco, Cal., 1890-91 ; Student in Chem- 
istry, University of California, 1891-93 ; 



Scholar in Chemistry, Clark Univer- 
sity, 1893-94. 

ERNEST ALBEE:— 

A.B., University of Vermont, 1887 ; 
Scholar in Philosophy, Clark Univer- 
sity, 1889-90 ; Fellow in Philosophy, 

1890-91 ; Fellow Sage School of Phi- 
losophy, Cornell University, 1891-92 ; 
Instructor in Philosophy, ibid., 1892- ; 
Ph.D., Cornell University, 1894; Mem- 
ber of the Am. Psy. Ass'n. 

Author of : — 

The Ethical System of Richard Cumber- 
land. Philosophical Review, May and 
July, 1895, Vol. 4, pp. 264-290 ; 371- 
393. 

The Relation of Shaftesbury and Hutche- 
son to Utilitarianism. Ibid., Jan., 

1896, Vol. 5, pp. 24-35. 

Gay's Ethical System. Ibid., March, 

1897, Vol. 6, pp. 132-145. 

Hume's Ethical System. Ibid., July, 
1897, Vol. 6, pp. 337-355. 

ARTHUR ALLIN: — 

A.B., Victoria University, Toronto, 1892 
(Double Gold Medalist in Classics and 
Philosophy) ; University of Heidelberg, 
1892 ; University of Breslau, 1892-93 ; 
Ph.D., Berlin University, 1895; Hono- 
rary Fellow in Philosophy, Clark 
University, 1895-96 ; Professor of Psy- 
chology and Education, Ohio University, 
1896-97 ; Professor of Psychology and 
Education, University of Colorado, 1897- ; 



460 



Titles of 



Consulting Psychologist, State Industrial 
School of Colorado. 

Author of : — 

TJeber das Grundprincip der Association, 

Berlin, 1895. 
The Recognition-Theory of Perception. 

Am. Jour, of Psy., Jan., 1896, Vol. 7, 

pp. 237-248. 
Recognition. Ibid., Jan., 1896, "Vol. 7, 

pp. 249-273. 
The Psychology of Tickling, Laughing, 

and the Comic (with G. S. Hall) . Ibid., 

Oct., 1897, Vol. 9, pp. 1-41. 
Pedagogy in Ohio. Trans. Ohio College 

Ass'n, 1897. 
ExtrarOrganic Evolution. Science, Feb. 

25, 1898, N. S., Vol. 7, pp. 267-269. 
Extra-Organic Evolution and Education. 

Northwestern Monthly, May and June, 

1899, Vol. 9, pp. 400-403; 436-439. 

LOUIS "W. AUSTIN: — 

A.B., Middlehury College, 1889; Stu- 
dent, University of Strassburg, 1889-90 
and 1891-93 ; FeUow in Physics, Clark 
University, 1890-91; Ph.D., University 
of Strassburg, 1893 ; Instructor in Physics, 
University of Wisconsin, 1893-96 ; Assist- 
ant Professor, ibid., 1896- ; Member of the 
Wisconsin Academy of Sciences. 

Author of : — 

Experimentaluntersuohungen iiber die 
elastische Langs- und Torsionsnach- 
wirkung in Metallen. Annalen der 
Physik und Chemie, 1893, N. F., Bd. 
60, pp. 659-677. 

The Effect of Extreme Cold on Magnet- 
ism. Physical Bevieio, March-AprU, 
1894, Vol. 1., pp. 381-382. 

An Experimental Research on the Lon- 
gitudinal and Torsional Elastic Fa- 
tigue. Ibid., May-Jime, 1894, pp. 
401-425. 

On Gravitational Permeability. (With 
Charles B. Thwing. ) Ibid. , Nov.-Dec. , 
1897, Vol. 5., pp. 294-300. 

Exercises in Physical Measurement. 
(With Charles B. Thwing.) AUyn 
and Bacon, Boston, 1896. 208 pp. 



N. P. AVERT; — 

A.B., Amherst College, 1891 ; Principal, 
Yates Academy, Chittenango, N. Y., 1891- 
95 ; Scholar in Psychology, Clark Uni- 
versity, Oct. , 1895-Jaii. , 1896 ; ad- 
mitted to the Massachusetts bar, June, 
1896. 

FRANK K. BAILEY : — 

S. B., Colorado College, 1898 ; Scholar in 
Physios, Clark University, 1898-99. 

THOMAS P. BAILEY, JR. : — 

A.B., South Carolina College, 1887 ; 
Principal Winyah School, Georgetown, 
S. C, 1887-88; Tutor in English and 
History, University of South Carolina, 
1888-89; A.M., University of South 
Carolina, 1889 ; Secretary, ibid., 1889-91 ; 
Ph.D., University of South Carolina, 
1891 ; Adjunct Professor of Biology, 
South Carolina College, 1891-92 ; Fellow 
in Psychology, Clark University, 
1892-93 ; Lecturer, South Carolina Col- 
lege for Women, 1893-94 ; Superinten- 
dent of Schools, Marion, S. C, 1894-95; 
Assistant Professor of Science and Art of 
Teaching, University of California, 1894- 
98 ; Associate Professor of Education as 
related to Character, ibid. , 1898-. 

Author of : — 

The Development of Character (Doctor's 

Thesis), 1891. 
Humanity of the Spiritual Life. Christian 

Thought, Oct., 1892. 
Ejective Philosophy. Am. Jour, of Psy., 

July, 1893, Vol. 5, pp. 465-471. 
Herbart and Character Culture. iSo. Ed. 

Jour. Dec. 1893-Jan. 1894. 
Psychology for Teachers. ' Proc. S. C. 

Teachers'' Ass^n, 1893. 
The Practice of Medicine and the Practice 

of Teaching. Ibid., 1894. 
Comparative Child-study Observations. 

Handbook HI. Soc. for Child-study, 

1895. 
The Teaching Force — its General Culture. 

Proc. Cal. Teachers'' Ass^n, 1894. 
Child-study for "Naturalists." Pacific 

Ed. Joiir., April-May, 1895. 



Published Papers. 



461 



The Education of the Human Animal. 
Proc. Cal. Teachers^ Ass''n, 1896. 

Adolescence. Ibid. , 1896. 

Child-study Notes. Overland Monthly 
(School Edition), 1896-97. 

Work and Play. Froc. Cal. Teachers^ 
Ass'n, 1896. 

Ethological Outlines. Oakland School Re- 
port, 1896-97. 

Ethology and Child-study. Northwestern 
Monthly, Nov., 1897, Jan., 1898. 

Ethology and Child-study. Proc. 8. Cal. 
Teachers' Ass'n, 1898. 

Eeformers in Ethology. Bui. No. 13, 
Library Univ. of Cal., 1899. 

Ethology : Standpoint, Method, Tentative 
Kesults. University Chronicle (Uni- 
versity of California), Dec, 1898, 
Feb., 1899. 

HENRY ROLFE BAKER: — 

A.B., Iowa College, 1882; A.M., 1885; 
B.D., Yale University, 1886; Congrega- 
tional Ministry, 1887 ; Graduate Student, 
Andover Theological Seminary, 1889-90 ; 
Hopkins Graduate Student in Philosophy 
and Comparative Religion, Harvard Di- 
vinity School, 1890-91 ; Student in 
Psychology, Clark Umversity, 1894- 
95 ; Fellow, 1895-97 ; Honorary 
FeUow, 1898-99. 

Author of : — 

The Position of Myth, Science, and Na- 
ture Study in the Philosophy of Edu- 
cation. 

FRANKLIN "W. BARRO'WS: 

A.B., Amherst College, 1885; Instructor 
in Sciences, Worcester Academy, 1885-88 ; 
A.M., Amherst College, 1888 ; Instructor 
in Natural Sciences, Central High School, 
Buffalo, N. Y., 1888-Jan. 1894; M.D., 
University of Buffalo, 189.3 ; Fellow in 
Physiology, Clark University, Jan.- 
June, 1894 ; Instructor in Zoology and 
Physiology, Central High School, Buf- 
falo, N. Y., 1894 ; Instructor in Histology 
and Biology, Medical Department of Uni- 
versity of Buffalo, 1894-97 ; Professor, 
ibid., 1897-. 



GEORGE H. C. L. BAtJR : — 

Academy of Hohenheim, 1878-79 ; Uni- 
versity of Munich, 1879-81 ; University 
of Leipzig, 1881-82; Ph.D., University 
of Munich, 1882 ; Assistant to Professor 
C. Kupffer, Munich, 1882-84; Assistant 
to Professor O. C. Marsh, Yale Univer- 
sity, 1884-90 ; Docent in Osteology 
and Paleontology, Clark University, 
1890-92 ; In charge of the Salisbury Ex- 
pedition to the Galapagos Islands, May- 
Oct, 1891 ; Assistant Professor, Osteology 
and Paleontology, University of Chicago, 
1892-95 ; Associate Professor, ibid., 1895- 
97. 
Died June 25, 1898. 

Author of : — 

Der Tarsus der Vogel und Dinosaurier. 
Eine Morphologische Studie. Inau- 
gural-dissertation. Univers. Miinchen. 
Leipzig, 1882, Wilh. Engelmann, pp. 
1-44, 2 taf. Same in Morph. Jahrb. , 
1883, Bd. 8, pp. 417-456, Taf. XIX. 
and XX. 

Der Carpus der Paarhufer. Eine Mor- 
phogenetische Studie. (Vorl. Mittheil.) 
Morph. Jahrb., 1884, Bd. 9, pp. 597- 
603. 

Dinosaurier und Vogel. Eine Erwieder- 
ung an Herrn. Prof. W. Dames in 
Berlin. Ibid., 1885, Bd. 10, pp. 446- 
454. 

Note on the Pelvis in Birds and Dinosaurs. 
American Naturalist, Dec, 1884, Vol. 

18, pp. 1273-1275. 

Bemerkungen uber das Beoken der Vogel 

und Dinosaurier. Moiph. Jahrb., 

1885, Bd. 10, pp. 613-616. 
Zur Morphologie des Tarsus der Sauge- 

thiere. Ibid., 1886, Bd. 10, pp. 458- 

461. 
On the Morphology of the Tarsus in the 

Mammals. American Naturalist, Jan., 

1885, Vol. 19, pp. 86-88. 
Ueber das Centrale Carpi der Saugethiere. 

Morph. Jahrb., 1885, Bd. 10, pp. 455- 

457. 
On the Centrale Carpi of the Mammals. 

American Naturalist, Feb., 1885, Vol. 

19, pp. 195-196. 



462 



Titles of 



Das Trapezium der Cameliden. Morph. 

Jahrb., 1885, Bd. 10, pp. 117-118. 
The Trapezium of the Camelidse. Ameri- 
can Naturalist, Feb., 1895, Vol. 19, pp. 

196-197. 
A Second Phalanx in the Third Digit of 

a Carinate-Bird's Wing. Science, May 

1, 1885, Vol. 5, p. 355. 
A Complete Pibula in an Adult Living 

Carinate-Bird. Ibid., May 8, 1885, 

Vol. 5, p. 375. 
On tlie Morphology of the Carpus and 

Tarsus of Vertebrates. American 

Naturalist, July, 1885, Vol. 19, pp. 

718-720. 
Zur Morphologie des Carpus und Tarsus 

der Wirbelthiere. Zool. Anz., 1885, 

No. 196, pp. 326-329. 
Zur Vijgel-Dinosaurier-Frage. Ihid., 1885, 

No. 200, pp. 441-443. 
Naohtragliohe Bemerkungen zu : Zur Mor- 
phologie des Carpus und Tarsus der 

Wirbelthiere {Zool. Anz., 1885, No. 

196). Ibid., 1885, No. 202, pp. 486- 

488. 
Zum Tarstis der Vogel. Ibid., 1885, No. 

202, p. 488. 
Note on the Sternal Apparatus in Iguano- 

don. Ibid. , 1885, No. 205, pp. 561-562. 
Einige Bemerkungen iiber die Ossification 

der "langen" Knochen. Ibid., 1885, 

No. 206, pp. 880-581. 
Bemerkungen iiber den ' ' Astralagus ' ' und 

das ' ' Intermedium tarsi ' ' der Sauge- 

thiere. Morph. Jahrb., 1886, Bd. 11, 

pp. 468-483, Taf. XXVII. 
Zur Moi'phologie des Carpus und Tarsus 

der Reptilien. (Vorl. Mittheil.) Zool. 

Anz., 1885, No. 208, pp. 631-639. 
Ueber das Arohipterygium und die Ent- 

■wicklung des Cheiropterygium aus dem 

Ichthyopterygium. (Vorl. Mittheil.) 

Ibid., 1885, No. 209, pp. 663-666. 
Preliminary Note on the Origin of Limbs. 

American Naturalist, Nov. 1885, Vol. 

19, p. 1112. 
Historische Bemerkungen. Internat. 

Monatschr. f. Anat. u. Hist., 1886, 

Bd. 3, pp. 3-7. 
Der alteste Tarsus (Archegosaurus). Zool. 

Anz., 1886, No. 216, pp. 104-106. 



The Oldest Tarsus (Archegosaurus). 
American Naturalist, Feb., 1886, Vol. 
20, pp. 173-174. 

W. K. Parker's Bemerkungen iiber Ar- 
chseopteryx, 1864, und eine Zusam- 
mensteUung der hauptsachlichsten 
Litteratur iiber diesen Vogel. Zool. 
Anz., 1886, No. 216, pp. ^106-109. 

The Intercentrum of Living Reptilia. 
American Naturalist, Feb., 1886, Vol. 
20, pp. 174-175. 

The Proatlas, Atlas and Axis of the Cro- 
codilia. Ibid., March, 1886, Vol. 20, 
pp. 288-293, 5 figs. 

Die zwei Centralia im Carpus von Sphe- 
nodon (Hatteria) und die Wirbel von 
Sphenodon und Gecko verticiDatus 
Laur (G. verus Gray). Zool. Anz., 
1886, No. 219, pp. 188-190. 

Herm Prof. K. Bardeleben's Bemerkungen 
Tiber "Centetes madagascariensis." 
Ibid., 1886, No. 220, pp. 219-220. 

Ueber die Kanale im Humerus der Am- 
nioten. Morph. Jahrb., Bd. 12, pp. 
299-305. 

Bemerkungen iiber Sauropterygia und 
lohthyopterygia. Zool. Anz., 1887, 
No. 221, pp. 245-252. 

Ueber das Quadratum der Saugethiere. 
Sitzungsber. Gesell. Morph. u. Phys- 
iol., Miinchen, 1886, pp. 45-57. 

On the Quadrate in the Mammalia. 
Quart. Jour. Micr. Set, 1886, Vol. 28, 
new ser., pp. 169-180. 

Ueber die Morphogenie der Wirbelsaule 
der Amnioten. Biol. Centralbl., 1886, 
Bd. 6, Nos. 11, 12, pp. 332-342, 353-363. 

The Intercentrum in Sphenodon (Hat- 
teria). American Naturalist, May, 
1886, Vol. 20, pp. 465-466. 

Berichtigung. Zool. Anz., 1886, No. 223, 
p. 323. 

The Ribs of Sphenodon (Hatteria). 
American Naturalist, 'Nov., 1886, Vol. 
20, pp. 979-981. 

Ueber die Homologien einiger Sohadel- 
knochen der Stegocephalen und Rep- 
tiUen. Anat. Anz., 1886, Jahrg. 1, 
pp. 348-350. 

Osteologisohe Notizen (iber Reptilien. 
Zool. Anz., 1886, No. 238, pp. 686-690. 



Published Papers. 



463 



Osteologisclie Notizen iiber Eeptilien. 
Fortsetzung I. Ibid., 1886, No. 240, 
pp. 733-743. 

On the Morphogeny of the Carapace of 
the Testudinata. American Natural- 
ist, Jan., 1887, Vol. 21, p. 89. 

Osteologisohe Notizen ilber Keptilien. 
Forsetzung II. Zool. Am., 1887, No. 
244, pp. 96-102. 

Erwiederung an Harm Dr. A. Gunther. 
Ibid., 1887, No. 245, pp. 120-121. 

Ueber Lepidosiren paradoxa Fitzinger. 
Zool. Jahrb., 1887, Bd. 2, pp. 575-583. 

Naohtragliche Notiz zu meinen Bemer- 
knngen : "Ueber die Homologien 
einiger Sohadelknochen der Stegoceph- 
alen und Eeptilien " in No. 13 des 
ersten Jahrgangs dieser Zeitsohrift. 
Anat. Am., 1887, Jahrg. 2, No. 21, 
pp. 657-658. 

On the Phylogenetic Arrangement of the 
Sauropsida. Jour, of Morph., Sept., 
1887, Vol. 1, pp. 93-104. 

Ueber die Abstammung der Amnioten 
Wirbelthiere. Biol. Centralbt, 1887, 
Bd. 7, No. 16, pp. 481-493. 

On the Morphology and Origin of the 
Ichthyopterygia. American Natural- 
ist, Sept., 1887, Vol. 21, pp. 837-840. 

On the Morphology of Kibs. Ibid., Oct., 

1887, Vol. 21, pp. 942-945. 
Beitrage zur Morphogenie des Carpus und 

Tarsus der Vetebraten. 1 Theil. 
Batrachia. Jena, Gustav Fischer, 

1888, pp. 1-86, Taf. I.-III. 

Ueber den Ursprung der Extremitaten 

der Ichthyopterygia. Bericht. iiber 

die SO. Versam. d. Oberrhein. Geolog. 

Vereins, Jan. 16, 1888, 4 pp., 1 taf. 
Dermoohelys, Dermatochelys oder Sphar- 

gis. Zool. Anz., 1888, No. 270, pp. 

44-45. 
Unusual Dermal Ossifications. Science. 

March 23, 1888, Vol. 11, p. 144. 
Notes on the American Trionychidse, 

American Naturalist, Dec, 1888, Vol, 

22, pp. 1121-1122. 
The Theory of the Origin of Species by 

Natural Selection. Ibid., Dec, 1888, 

Vol. 22, p. 1144. 
Osteologische Notizen iiber Keptilien. 



Fortsetzung III. Zool. Am., 1888, No. 

285, pp. 417-424. 
Osteologische Notizen iiber Keptilien. 

Fortsetzung IV. Ibid., 1888, No. 291, 

pp. 592-597. 
Osteologische Notizen uber Keptilien. 

Fortsetzung V. Ibid., 1888, No. 296, 

pp. 736-740. 
Osteologische Notizen iiber Keptilien. 

Fortsetzung VI. Ibid., 1889, No. 298, 

pp. 40-47. 
Revision meiner Mittheilungen im zool- 

ogischen Anzieger, mit Naohtragen. 

Ibid., 1889, No. 306, pp. 238-243. 
Neue Beitrage zur Morphologie des Carpus 

der Saugethiere. Anat. Anz., 1889, 

Jahrg. 4, No. 2, pp. 49-51, 4 figs. 
The Systematic Position of Meiolania, 

Owen. Ann. Mag. Nat. Hist., (6) 

Jan., 1889, Vol. 3, pp. 54-62. 
On " Aulacochelys," Lydekker, and the 

Systematic Position of Anosteira, and 

Pseudotrionyx, Dollo. Ibid., 1889, (6) 

Vol. 3, pp. 273-276. 
On Meiolania and Some Points in the 

Osteology of the Testudinata : a Keply 

to Mr. G. A. Boulenger. Ibid., 1889, 

(6) Vol. 4, pp. 37^5, PI. vi. 
Mr. E. T. Newton on Fterosauria. Ibid., 

1889, pp. 171-174. 
Die systeraatische Stellung von Dermo- 
ohelys Blainv. Biol. Centralbl., 1889, 

Bd. 9, Nos. 5 und 6, pp. 149-153, 180- 

191. 
Nachtragliche Bemerkungen uber die sys- 

tematische Stellung von Dermoohelys 

Blainv. Ibid., 1889, Bd. 9, Nos. 20 und 

21, pp. 618-619. 
Palseohatteria Credner and the Progano- 

sauria. Am. Jour, of Set, April, 1889, 

Vol. 37, pp. 310-313. 
Kadaliosaurus priscus Credner, a new 

Reptile from the Lower Permian of 

Saxony. Ibid., Feb., 1890, pp. 156- 

158. 
Bemerkungen iiber den Carpus der Pro- 

boscidier und der Ungulaten im Alge- 

meinen. Morph. Jahrb., 1889, Bd. 15, 

Heft 3, pp. 478^82, 1 fig. 
On the Morphology of Ribs and the Fate 

of the Actinosts of the Median Fins in 



464 



Titles of 



Fishes. Jour, of Morph., Dec, 1889, 
Vol. 3, pp. 463-466, 7 figs. 

On the Morphology of the Vertebrate- 
Skull. Ibid., 1889, Vol. 3, No. 3, pp. 
467-474. 

A Review of the Charges against the 
Paleontological Department of the 
U. S. Geological Survey, and of 
the Defence made by Prof. 0. C. 
Marsh. American Naturalist, March 
26, 1890, Vol. 24, pp. 298-304. 

Note on Carettochelys, Ramsay. Ibid., 
Nov., 1889, Vol. 23, p. 1017. 

The Gigantic Land Tortoises of the Gala- 
pagos Islands. Ibid., Dec, 1889, Vol. 
23, pp. 1039-1057. 

The Relationship of the Genus Dirochelys. 
Ibid., Dec, 1889, Vol. 23, pp. 1099- 
1100. 

The Genera of the Podoonemididse. Ibid., 
May, 1890, Vol. 24, pp. 482-484. 

Note on the Genera Hydraspis and Rhine- 
mys. Ibid., May, 1890, Vol. 24, pp. 
484-485. 

The Genera of the CheloniidEe. Ibid., 
May, 1890, Vol. 24, pp. 486-487. 

On the Classification of the Testudinata. 
Ibid., June, 1890, Vol. 24, pp. 530- 
536. 

Professor Marsh on Hallopus and Other 
Dinosaurs. Ibid. , June, 1890, Vol. 24, 
pp. 569-571. 

An Apparently New Species of Chelys. 
Ibid., Oct. 1890, Vol. 24, pp. 967-968. 

On the Characters and Systematic Posi- 
tion of the Large Sea Lizards, Mosa- 
sauridEB. Science, Nov. 7, 1890, Vol. 
16, No. 405, p. 262. 

Two New Species of Tortoises from the 
South. Ibid., Nov. 7, 1890, Vol. 16, 
No. 405, pp. 262-263. 

The Problems of Comparative Osteology. 
Ibid., 1890, Vol. 16, No. 407, pp. 281- 
282. 

Das Variieren der Eidechsen-Gattung 
Tropidurus auf den Galapagos Inseln 
und Bemerkungen fiber den Ursprung 
der Inselgruppe. Biol. Centralbl., 
1890, Bd. 10, Nos. 15 und 16, pp. 475- 
483. 

The Very Peculiar Tortoise, Carettochelys 



Ramsay, from New Guinea. Science, 

Apr. 3, 1891, Vol. 17, No. 426, p. 190. 
American Box Tortoises. Ibid., Apr. 3, 

1891, Vol. 17, No. 426, pp. 190-191. 
The Horned Saurians of the Laramie 

Formation. Ibid., Apr. 17, 1891, Vol. 

17, No. 428, pp. 216-217. 
The Lower Jaw of Sphenodon. American 

Naturalist, May, 1891, Vol. 25, pp. 

489-490. 
Notes on the Trionychian Genus Peloche- 

lys. Ann. Mag. Nat. Hist., May, 1891, 

(6) Vol. 7, pp. 445-446. 
Remarks on the Reptiles generally called 

Dinosauria. American Naturalist, 

May, 1891, Vol. 25, pp. 434-454. 
On the Origin of the Galapagos Islands. 

Ibid., March and April, 1891, Vol. 25, 

pp. 217-229, 307-326. 
On the Relations of Carettochelys, Ram- 
say. Ibid., July, 1891, Vol. 25, pp. 

631-639, Pis. x.-xvi. 
On Intercalation of Vertebrae. Jour, of 

Morph., Jan., 1891, Vol.4, pp. 331-336. 
The Pelvis of the Testudinata, with Notes 

on the Evolution of the Pelvis in 

General. Ibid., 1891, Vol. 4, No. 3, pp. 

345-359, 13 figs. 
Notes on Some Little-known American 

Fossil Tortoises. Proc. Acad. Nat. 

Sci. Phil., 1891, pp. 411-430. 
[Dr. Baur's Trip to the Galapagos 

Islands.] Americaii Naturalist, Oct., 

1891, Vol. 25, pp. 902-907. 

The Galapagos Islands. Proc. Am. Ant. 
Soc, Oct. 21, 1891, pp. 3-8. 

Das Variieren der Eidechsen-Gattung 
Tropidurus auf den Galapagos-Inseln. 
Festschr. z. 70. Geburtstage R. Leuck- 
arts. Leipzig, 1892, Wilhelm Engel- 
mann, pp. 259-277. 

Professor Alexander Agassiz on the Origin 
of the Fauna and Flora of the Gala- 
pagos Islands. Science, March 25, 

1892, Vol. 19, No. 477, p. 176. 

Der Carpus der Schildkroten. Anat. 

Anz., 1892, Jahrg. 7, Nos. 7 und 8, 

pp. 206-211, 4 figs. 
On the Taxonomy of the Genus Emys, 

C. Dum^ril. Proc. Am. Phil. Soc, 

1892, Vol. 30, pp. 40-44. 



Published Papers. 



465 



Addition to the Note on the Taxonomy 

of the Genus Emys, C. Dum^ril. Ibid., 

1892, Vol. 30, p. 245. 
On Some Peculiarities in the Structure of 

the Cervical Vertebree in the Existing 

Monotremata. American Naturalist, 

Jan., 1892, Vol. 26, p. 72. 
[Visit to the Galapagos Islands.] Proc. 

Bost. Soc. Nat. Hist., March, 1892, 

Vol. 25, p. 317. 
The Cervical Vertebrse of the Monotre- 
mata. American Naturalist, May, 

1892, Vol. 26, p. 435. 
Bemerkungen iiber verschiedene Arten 

von Sohildkroten. Zool. Am., 1892, 

No. 389, pp. 155-159. 
Ein Besuch der Galapagos-Inseln. Biol. 

Centrum., 1892, Bd. 12, pp. 221-250. 
On the Morphology of the Skull in the 

Mosasauridse. Jour, of Morph., Oct., 

1892, Vol. 7, pp. 1-22, Pis. i. and ii. 
Notes on the Classification and Taxonomy 

of the Testudinata. Proc. Am. Phil. 

Soc, May 5, 1893, Vol. 31, pp. 210-225. 

Notes on the Classification of the Crypto- 

dira. American Naturalist, July, 

1893, Vol. 27, pp. 672-675. 

Two New Species of North American Tes- 
tudinata. Ibid., July, 1893, Vol. 27, 

pp. 676-677. 
Further Notes on American Box-Tortoises. 

Ibid., July, 1893, Vol. 27, pp. 677-678. 
G. Jager und die Theorie von der Conti- 

nuitat des Keimprotoplasmas. Zool. 

Am., 1893, No. 425, p. 300. 
Ueber Eippen und ahnliohe Gebilde und 

deren Nomenclatur. Anat. Am., 1893, 

Jahrg. 9, No. 4, pp. 116-120. 
The Discovery of Miocene Amphisbsenians. 

American Naturalist, Nov., 1893, Vol. 

27, pp. 998-999. 
The Relationship of the Lacertilian Genus 

Anniella Gray. Proc. U. 8. Nat. 

Mus., Vol. 17, No. 1005, pp. 845-351. 
Bemerkungen iiber die Osteologie der 

Schlafengegend der hoheren Wirbel- 

thiere. Anat. Am., Dec, 1894, Bd. 10, 

No. 10, pp. 315-330. 
Ueber den Proatlas einer Sohildkrote (Pla- 

typeltis spinifer Les.). Ibid., Jan., 

1895, Bd. 10, No. 11, pp. 349-354, 6 figs. 
2h 



Die Palatingegend der Ichthyosauria. 
Ibid., 1895, Bd. 10, No. 14, pp. 456- 
459, 1 fig. 

The Differentiation of Species on the 
Galapagos Islands and the Origin of 
the Group. Biol. Lect. M. B. L. 
Woods Holl, 1895, pp. 67-78. 

Pithecanthropus erectus. Jour. Geol., 
Eeb. and March, 1895, Vol. 3, No. 2, 
pp. 237-238. 

The Fins of Ichthyosaurus. Ibid., Feb. 
and March, 1895, Vol. 3, No. 2, pp. 
238-240. 

The Experimental Investigation of Evolu- 
tion. The Dial, May 1, 1893, p. 278. 

Cope on the Temporal Part of the Skull, 
and on the Systematic Position of the 
Mosasaurid^. A Reply. American 
Nattwalist, Nov., 1895, Vol. 29, pp. 
998-1002. 

Ueber die Morphologic des Unterkiefers 
der Reptilien. Anat. Am., 1896, Bd. 
11, No. 13, pp. 410-415, 4 figs. 

Das Gebiss von Sphenodon (Hatteria) 
und einige Bemerkungen iiber Prof. 
Eud. Burckhardt's Arbeit iiber das 
Gebiss der Sauropsiden. Anat. Am. , 
1895, Bd. 11, No. 14, pp. 436^39. 

The Paroccipital of the Squamata and the 
Affinities of the Mosasauridse Once 
More. A Rejoinder to Prof. E. D. 
Cope. American Naturalist, Feb., 1896, 
Vol. 30, pp. 143-147, PI. iv. 

Nachtrag zu meiner Mittheilung iiber die 
Morphologie des Unterkiefers der Rep- 
tilien. Anat. Anz., 1896, Bd. 11, Nos. 
18 und 19, p. 569. 

Review of Dr. A. E. Ortmann's " Grund- 
ziige der marinen Thiergeographie." 
Science, March 6, 1896, Vol. 3, No. 62, 
pp. 359-367. 

The Stegocephali. A Phylogenetic Study. 
Anat. Am., 1896, Bd. 11, No. 22, pp. 
657-673, 8 figs. 

Mr. Walter E. CoUinge's "Remarks on 
the Preopercular Zone and Sensory 
Canal of Polypterus." Ibid., 1896, Bd. 
11, Nos. 9 und 10, pp. 247-248. 

Professor Cope's Criticisms of my Draw- 
ings of the Squamosal Region of Cono- 
lophus subcristatus Gray (^American 



466 



Titles of 



Naturalist. Feb., 1896, pp. 148-149), 
and a Few Remarks about his Draw- 
ings of the Same Object from Stein- 
dachner. /Sic?., April, 1896, Vol. 30, 
pp. 327-329. 

Bemerkungen zu Prof. Dr. O. Bottger's 
Keferat tiber : Seeley, H. G. on Theoo- 
dontosaurus and Palaeosaurus. Zool. 
Centralbl., Jahrg. 3, No. 11, 1896, 
p. 896. 

Der Schadel einer neuen, grossen Schild- 
krote (Adeloohelys) aus dem zoologis- 
chen Museum in Miinchen. Anat. 
Anz., 1896, Bd. 12, Nos. 12 und 18, 
pp. 314-319, 4 figs. 

Bemerkungen uber die Phylogenie der 
Schildkroteu. Ibid., 1896, Bd. 12, Nos. 
24 und 25, pp. 561-570. 

On the Morphology of the Skull of the 
Pelycosauria and the Origin of Mam- 
mals. (With E. C. Case.) /5iU, 1897, 
Bd. 13, Nos. 4 und 5, pp. 109-120, 
3 figs. 

Remarks on the Question of Intercalation 
of "Vertebrae. Zoological Bulletin, 
Aug., 1897, Vol. 1, No. 1, pp. 41- 
55. 

Birds of the Galapagos Archipelago : A 
Criticism of Mr. Robert Ridgway's 
Paper. American Naturalist, Sept., 
1897, Vol. 31, pp. 777-784. 

Archegosaurus [Review of 0. Jackels's 
"Die Organisation von Archegosau- 
rus"]. Ibid., Nov., 1897, Vol. 31, pp. 
975-980. 

New Observations on the Origin of the 
Galapagos Islands, with Remarks on 
the Geological Age of the Pacific 
Ocean. Ibid., Aug., 1897, Vol. 31, pp. 
661-680, and Oct., 1897, pp. 864-896 
(incomplete) . 

HENRY BBNNER:— 

B.S., State Normal School, West Chester, 
Pa., 1885; M.S., ibid, 1887, and Uni- 
versity of Michigan, 1889 ; Fellow in 
Mathematics, Clark University, 1889- 

90 ; Instructor in Mathematics, Prepara^ 
tory School, Northwestern University, 
1890-92 ; Instructor in Mathematics, 
Chicago Manual Training School, 1892-. 



JOHN A. BEHGSTROM: — 

A.B., Wesleyan University, Middletovsm, 
Conn., 1890 ; Fellow in Psychology, 
Clark University, 1891-94; Ph.D., 
Clark University, 1894 : Assistant Pro- 
fessor of Psychology and Pedagogy, 
Indiana University, 1894-96 ; Associate 
Professor of Psychology and Pedagogy, 
ibid, 1896-. 

Author of : — 

Experiments upon Physiological Memory 
by Means of the Interference of Asso- 
ciations. Am. Jour, of Psy., April, 

1893, Vol. 5, iDp. 356-369. 

An Experimental Study of Some of the 
Conditions of Mental Activity. Ibid., 
Jan., 1894, Vol. 6, pp. 247-274. 

The Relation of the Interference to the 
Practice Effect of an Association. 
Ibid., June, 1894, Vol. 6, pp. 433-442. 

School Hygiene. (Translation of Dr. 
Ludwig Kotelmann's Ueber Schul- 
gesundlieitspflege. With Edward Con- 
radi.) Bardeen, Syracuse, N. Y., 1899, 
391 pp. 

ADOLF BERNHARD: — 

A.B., Johns Hopkins University, 1889 ; 
Teacher of Mathematics and Science, 
National German-American Teachers' 
Seminary, Milwaukee, Wis., 1889-91 ; 
Fellow in Chemistry, Clark Univer- 
sity, 1891-92 ; Fellow in Chemistry, 
University of Chicago, 1892-94 ; Ph.D., 
University of Chicago, 1894 ; Laboratory 
Assistant in Chemistry, ibid., 1894-95. 

Author of : — 

Ueber die Einftihrung von Acylen in den 
Benzoylessigather (Thesis). Chicago, 

1894, pp. 43. 

FRANZ BOAS:— 

Ph.D., Kiel, 1881 ; Expedition to Baffin 
Land, 1883-84 ; Privatdocent, University 
of Berlin, Assistant Royal Ethnographi- 
cal Museum of Berlin, 1884-86 ; Expedi- 
tion to British Columbia, 1886-87 ; As- 
sistant editor of Science, 1887-89 ; Do- 
cent in Anthropology, Clark Univer- 
sity, 1889-92 ; Chief Assistant, Depart- 



Published Papers. 



467 



ment of Anthropology, World's Colum- 
bian Exposition, Cliicago, 1892-94 ; Ex- 
pedition to Alaska, Britisli Columbia, and 
California, 1896 ; Assistant Curator, 
Department of Anthropology, American 
Museum of Natural History, New York, 
1896- ; Lecturer on Anthropology, Colum- 
bia University, 1896-99 ; Professor of An- 
thropology, ibid., 1899- ; Member of : the 
New York Academy of Sciences, the 
American Statistical Association, the 
American Psychological Association, the 
American Folk-Lore Society, the Berlin 
Anthropological Society, the Berlin Geo- 
graphical Society ; Corresponding mem- 
ber of the Anthropological Society of 
Vienna, the Imperial Society of Friends 
of Natural Sciences, Anthropology, and 
Ethnology at Moscow, the Roman An- 
thropological Society, the Anthropological 
Society of Paris, the Anthropological 
Society at Washington, the American 
Antiquarian and Numismatic Society of 
Philadelphia ; Past Vice-President of the 
Anthropological Section of the American 
Association for the Advancement of 
Science ; Associate Editor of the Inter- 
nationales Archiv fur Ethnographie, and 
of the American Anthropologist, N. S. 

Author of : — 

Beitrage zur Erkenntniss der Earbe des 
Wassers. Inaugural Dissertation. Kiel, 
1881. 

Ein Beweis des Talbotsohen Satzes. An- 
nalen der Fhysik und Chemie, 1882, 
pp. 359-362. 

Ueber eine neue Form des Gesetzes der 
TJnterschiedsschwelle. Pfluger^s Ar- 
chiv, 1881, pp. 493-500. 

Ueber die verschiedenen Eormen des 
Unterschiedsschwellenwerthes. Ibid., 
1882, pp. 214-222. 

Ueber die Berechnung der Unterschieds- 
schwelle nach der Methode der richti- 
gen und falschen Falle. Ibid., 1882, 
pp. 84-94. 

Die Bestimmung der Unterschiedsemp- 
findliclikeit nach der Methode der 
tibermerklichen Untersohiede. Ibid., 
1882, pp. 562-566. 



Ueber die Grundaufgabe der Psycho- 
physik. Ibid., 1882, pp. 566-576. 

Ueber den Unterschiedsschwellenwerth 
als das Mass der Intensitat psychischer 
Vorgiinge. Philosophische Monats- 
hefte, 1882, pp. 367-375. 

Ueber die ehemalige Verbreitung der 
Eskimos im arktisch-amerikanischen 
Archipel. Zeitschrift der Gesellschaft 
fur Erkunde, 1883, pp. 118-136. 

Die Wohnsitze der Neitohillik Eskimos. 
Ibid., 1883, pp. 161-172. 

Arctic Exploration and its Object. Pop. 
Sci. Mon., May, 1885, Vol. 27, pp. 
78-81. 

Bemerkungen zur Topographic der Hud- 
son Bay. Petermami's Mittheilungen, 
1885, pp. 424-426. 

Baffin Land. Geographisohe Ergebnisse 
einer in den Jahren 1883 und 1884 un- 
ternommenen Forschungsreise. Gotha, 
1885, 104 pp., 2 maps. 

Die Sprache der Bella Coola Indianer. 
Verh. Anthrop. Oes., Berlin, 1886, pp. 
202-206. 

Zur Ethnologie von Britisch Columbien. 
Petermami's Mittheilungen, 1887. 

Mittheilungen uber die Bilqula Indianer. 
Originalmittheilimgen aus dem K. 
Museum fur Volkerkunde, Berlin, 
1885, pp. 177-182. 

On certain songs and dances of the Kwa- 
kiutl Indians. Jour. Am. Folk-Lore, 
April-June, 1888, Vol. 1, pp. 49-64. 

Meteorologische Beobachtungen im Cum- 
berland Sunde. Annalen der Hydro- 
graphie, 1888, pp. 241-262. 

The Game of Cat's Cradle. Internatio- 
nales Archiv far Ethnographie, 1888. 

Chinook Songs. Joiir. Amer. Folk-Lore, 
1888, pp. 220-226. 

Das Fadenspiel. Mittheilungen der An- 
thropologischen Gesellschaft, Vienna, 
1888, p. 85. 

Sagen der Eskimos von Baffin Land. 
Verh. der Berliner Anthropologischen 
Gesellschaft, 1888, pp. 398-405. 

The Study of Geography. Science, 1887, 
Vol. 9, p. 157. 

Arrangement of Ethnological Collections. 
Ibid., 1887, Vol. 9, pp. 485, 687, 614. 



468 



Titles of 



Ice and loetergs. Ibid., 1887, Vol. 9, 

p. 324. 
Formation and Dissipation of Seawater 

Ice. Tbid., Vol. 10, p. 118. 
The Eskimo Tribes. Review of Rink's 

Eskimo Tribes. Ibid., Vol. 10, p. 271. 
Eskimo and Indian. Ibid., Vol. 10, p. 

273. 
The Central Eskimo. Sixth An. Hep. 

Bur. Ethn., Washington, 1888, pp. 

399-669. 
Die Eisverhaltnisse des sMbstlichen 

Theiles von BaflBn-Land. Peter- 

mannas Mittheilungen, 1888, pp. 296- 

298, 18 plates. 
Eskimo Tales and Songs (Texts). H. 

Rink and F. Boas. Jour. Am. Folk- 

Lore, Vol. 2, pp. 123-131. 
Notes on the Snanaimuq. American 

Anthropologist, 1889, pp. 321-328. 
Die Ziele der Ethnologic. New York, 

1889, 30 pp. 

Fourth Report of the Committee on the 
Northwestern Tribes of Canada. British 
Ass^n Adv. Science, 1888, pp. 1-10. 

Fifth Report of the Committee, 1889, pp. 
1-96. 

Sixth Report, 1890, pp. 1-163. 

Seventh Report, 1891, pp. 1-40, 4 tables. 

Ninth Report, 1894, pp. 1-16. 

Tenth Report, 1895, pp. 1-74, 11 tables. 

Eleventh Report, 1896, pp. 1-23. 

A Critique of Psycho-Physic Methods. 
Science, Vol. 11, p. 119. 

The Indians of British Columbia. Pop. 
Sci. Mon., March, 1888, Vol. 32, pp. 
628-636. 

Is Stanley Dead ? Nor. Am. Bev., 1888. 

On Alternating Sounds. American An- 
thropologist, 1889, pp. 47-53. 

On the Census Maps of the United States. 
Science, Vol. 12. 

Cranium from Yucatan. Am. Antiq. Soc, 

1890, pp. 350-357. 

The Use of Masks and Head Ornaments 
in British Columbia. Intern' I Arch. 
Eth., 1890. 

Mixed Races. Science, 1891, Vol. 17, p. 
179. 

Dissemination of Tales in America. Jojir. 
Am. Folk-Lore, 1891, pp. 13-30. 



Petroglyph in Vancouver Island. Verh. 
der. Berliner Ges. fur Anth., 1891, pp. 
158-159. 

Sagen der Kootenay. Ibid., pp. 159- 
172. 

Notes on the Chemakum Language. Amer- 
ican Anthropologist, 1892, pp. 37^4. 

Vocabularies from the North Pacific 
Coast. Trans. Am. Phil. Soc, 1891, 
pp. 30. 

Chinook Jargon. Science, Vol. 19, p. 474. 

The Growth of Children. Ibid., Vol. 
19, pp. 256-258, 281-283. 

Anthropologie in Amerika. Correspon- 
denzblatt deutsch. Anth. Gesellschaft, 
1892, pp. 114-116. 

Notes on the Chinook Language. Ameri- 
can Anthropologist, 1883, pp. 55-63. 

The Growth of Children. Science, 1892, 
Vol. 26, p. 351. 

Vocabulary of the Kwakiutl Language. 
Am. Phil. Soc, 1892, pp. 34-82. 

Eskimo Songs and Tales. Jour. Am. 
Folk-Lore, 1894, pp. 46-50. 

Correlation of Anatomical and Physiolog- 
ical Measurements. American Anthro- 
pologist, 1894, pp. 313-324. 

Linguistische Resultate einer Reise in 
BaflSn Land. Mittheilungen der An- 
thropologischen Gesellschaft, Vienna, 
1894, pp. 97-114. 

Anthropology of the North American 
Indians. InternH Cong. Anth., Chicago, 
1894, pp. 37-49. 

Classification of Languages of the North 
Pacific Coast. Ibid., pp. 339-346. 

Omaha Music. Review. Jour. Am. 
Folk-Lore, 1894, pp. 169-170. 

Remarks on the Theory of Anthropome- 
try. International Statistical Con- 
gress, Chicago. Quar. Jour. Amer. 
Stat. Soc, 1893. 

The Half-blood Indian. Pop. Sci. Mon., 
October, 1894. 

Human Faculty as Determined by Race. 
A. A. A. S., 1894. Reprint, pp. 1-27. 

Chinook Texts. Bulletin, Bureau oj 
Ethnology, Washington, D.C., 1894, 
pp. 1-278. 

Salishan Texts. Am. Philos. Soc, 1895, 
pp. 31-48. 



Published Papers. 



469 



Notes on the Eskimo of Port Clarence, 
Alaska. Jour. Am. Folk-Lore, 1894, 
pp. 205-208. 
Zur Mythologie der Indianer von Wash- 
ington und Oregon. Globus, 1893, 
Nos. 10-12. 
Dr. W. T. Porter's Investigations on the 
Grovrth of the School Children of St. 
Louis. Science, March 1, 1895, pp. 
225-230. Correspondenzblatt der deut- 
schen Anth. Ges., 1895. 
The Growth of First-born Children. 

Science, April 12, 1895. 
Zur Ethnologie von Britisch Columbien. 
Verh. d. Ges. fiir Erdkunde, Berlin, 
May 4, 1895. 
Indianische Sagen von der Nordpacifischen 
Ktiste. A. Asher, Berlin, 1895. vi. 
-I- 364 pp. 
The Relations Between Length-hreadth 
and Length-height Index of the Skull. 
Verh. Berliner Ges. fiir Anthropologic. 
The Growth of United States Naval 
Cadets. Science, N. S., Vol. 2, pp. 
344-346. 
Anthropometry of the Indians of Southern 
California. Am. Ass'n for the Adv. 
Sci., 1895, pp. 261-269, 9 tables. 
Zur Anthropologie der Indianer Nord 
Amerikas. Verh. der Berliner Anth. 
Ges., 1895, pp. 366-411. 
Sprachen Karte von Britisch Columbien. 
Petermann's Mittheilungen, 1896, No. 
1, 2 plates. 
The Growth of Indian Mythologies. 
Jour. Am. Folk-Lore, 1896, pp. 1-12. 
Livi. Antropometria Militare. Review. 

Science, N. S., Vol. 3, pp. 929 ff. 
The Growth of the Head. Ibid., N. S., 

Vol. 4, No. 80. 
Songs of the Kwakiutl Indians. Int. 
Archiv fiir Ethnographie, IX., 1896, 
pp. 1-9. 
The Limitations of the Comparative 
Method of Anthropology. Science, 
Dec. 18, 1896, pp. 901-908. 
Traditions of the T'sets'a' ut. Jour. Am,. 
Folk-Lore, Vol. 9, pp. 257-268 ; Vol. 
10, pp. 35-48. 
The Growth of Children. Science, Vol. 
6, pp. 570-573. 



The Decorative Art of the Indians of the 
North Pacific Coast. Bull. Amer. Mus. 
Nat. Sis., 1897, pp. 123-176. 

Eskimo Songs. Jour. Am. Folk-Lore, 
1897, pp. 109-115. 

Northern Elements in the Mythology of 
the Navaho. American Anthropolo- 
gist, 1897, pp. 371-376. 

Social Organization and Religious Cere- 
monials of the Kwakiutl Indians. 
Report of the U. S. National Museum 
for 1895. Washington, 1897, pp. 311- 
736. 

Traditions of the Tillamook. Jour. Am. 
Folk-Lore, 1898, pp. 23-38, 133-150. 

Ehrenreich ; Die Ureinwohner Brasiliens. 
Science, N. S., Vol. 6, pp. 880-883. 

Introduction to James Teit. Traditions 
of the Thompson River Indians of 
British Columbia, 1898, pp. 1-18. 

The Growth of the School Children of 
Toronto. Annual Beport of the Com- 
missioner of Education, 1896-97. 
Washmgton, 1898, Vol. 2, pp. 1541- 
1599. 

Cathlamet Texts. Nineteenth Annual 
Beport of the Bureau of Ethnology, 
200 pp. 

Nisqa Texts. Ibid., 100 pp. 

Facial Paintings of the Indians of North- 
. em British Columbia. Memoirs Am. 
Mus. Nat. His., Vol. 2, pp. 1-24. 

Mythology of the Bella Coola Indians, 
lUd., pp. 25-127. 

A Precise Criterion of Species. Science, 
Vol. 7, No. 182, pp. 860-861. 

Twelfth Report of the Committee of the 
British Association for the Advance- 
ment of Science on the Northwestern 
Tribes of Canada (with Dr. Living- 
ston Farrand) . Proc. of theB.A.A.S., 
Bristol Meeting, 1898, pp. 1-61, 12 
tables. 
Anthropologie in Nord Amerika. Cor- 
respbl. der deuts. Ges. f. Anthrop., 
1898. 
Mittheilungen aus Amerika. Ibid., 1898, 

Jahrg. 29, pp. 121-123. 
Some Recent Criticisms of Physical An- 
thropology. American Anthropologist, 
Jan., 1899, N. S., Vol. 1, pp. 98-106. 



470 



Titles of 



The Cephalic Index. Ihid., July, 1899, 
N. S., Vol. 1, pp. 448-461. 

EUGENE W. BOHANNON : — 

Graduate, Indiana State Normal School, 
1887; Superintendent of Schools, Browns- 
burg, Ind., 1887-88; A.B., Indiana Uni- 
versity, 1890 ; Superintendent of Schools, 
Plainfleld, Ind., 1889-91 ; Principal, High 
School, Pekin, 111., 1891-92; A.M., In- 
diana University, 1892 ; Superintendent 
of Schools, Rensselaer, Ind., 1892-95; 
Scholar in Pedagogy, Clark Univer- 
sity, 1895-96 ; FeUow in Psychology, 
1896-98 ; Professor of Psychology, 
Pedagogy, and Practice, State Normal 
School, Mankato, Minn., 1898-. 

Author of : — 

Peculiar and Exceptional Children. Ped- 
agogical Seminary^ Oct., 1896, Vol. 4, 
pp. 3-60. 

The Only Child in a Family. Ibid., 
April, 1898, Vol. 5, pp. 475-496. 

The Undue Emphasis of Method, hid. 
School Jour., Jan., 1899, pp. 1-7. 

FREDERICK E. BOLTON: — 

Graduate, State Normal School, Milwau- 
kee, Wis., 1890; Principal, High School, 
Eairchild, Wis., 1890-91; B.S., Univer- 
sity of Wisconsin, 1893 ; Principal of 
Schools, Kaukauna, Wis., 1893-95; M.S., 
University of Wisconsin, 1896 ; Univer- 
sity of Leipzig, Germany, 1896-97 ; Hon- 
orary FelloTW in Psychology, Clark 
University, 1897-98; Ph.D., Clark 
University, 1898 ; Professor of Psy- 
chology and Pedagogy, State Normal 
School, Milwaukee, Wis., 1898- ; Mem- 
ber, Wisconsin Educational Cluh; Past 
Vice President, Wisconsin Child Study 
Society ; Member, Wisconsin State Teach- 
ers' Association. 

Author of : — ■ 

The Accuracy of Recollection and Obser- 
vation. Psychological Beview, May, 
1896, Vol. 3, pp. 286-295. 

The Development of School Curricula in 
the United States. Thesis deposited 



in Library of University of Wisconsin, 
1896, pp. 206. 

Apperception in the Study of Geography. 
Wis. Jour. Ed., Aug., 1896. 

The Importance of Higher Education to 
the Teacher. Ibid., Sept., 1890. 

The Training of Elementary Teachers in 
. Germany. Ibid., April, 1896. 

Elementary Schools in Germany. Ibid., 
June, 1897. 

A Contribution to the Study of Illusions. 
Am. Jour, of Psy., Jan., 1898, Vol. 9, 
pp. 167-182. 

Hydro-Psychoses (Doctorate Disserta- 
tion). Ibid., Jan., 1899, Vol. 10, pp. 
171-227. 

Scientific and Practical Child-study : The 
Province and the Limitations of Each. 
Wis. Jour. Ed., May, 1899, and Child 
Study Monthly, May, 1899, Vol. 5, 
pp. 7-24. 

The Secondary School System of Ger- 
many. The Internat. Ed. Series. D. 
Appleton & Co. (In press.) 

THADDEUS L. BOLTON: — 

A.B., University of Michigan, 1889; 
Principal, Public Schools, Vulcan, Mich., 
1889-90; Scholar in Psychology, Clark 
University, 1890-91 ; Fellovir and As- 
sistant, 1891-92 ; FeUow and Demon- 
strator, 1892-93 ; Assistant in Ethnol- 
ogy, World's Columbian Exposition, 1893 ; 
Teacher in Psychology, State Normal 
School, Worcester, Mass., 1893-1896; 
Ph.D., Clark University, 1895 ; Pro- 
fessor of Psychology and Pedagogy, State 
Normal School, San Jos6, Cal., 1896-97; 
Professor of Philosophy and Education, 
University of Washington, Seattle, Wash., 
1897-98 ; University of Heidelberg, 1898- 
99. 

Author of : — 

Brain Model on a Large Scale, by Dr. 
Azoux. Translation. (With H. H. 
Donaldson.) Am. Jour, of Psy., 
April, 1891, Vol. 4, pp. 132-141. 

The Size of the Several Cranial Nerves in 
Man, as indicated by the Areas of 
their Cross-sections. (With H. H. 



Published Papers. 



471 



Donaldson. {Ihid., Deo., 1891, Vol. 
4, pp. 224-229. 

The Growth of Memory in School Chil- 
dren. Ibid., April, 1892, Vol. 4, pp. 
362-380. 

A Study of the Spinal Cord of a Spring- 
halt Horse. Jour, of Nervous and 
Mental Diseases, Jan., 1893, N. S., 
Vol. 18, pp. 7-12. 

On the Discrimination of Groups of Rapid 
Clicks. Am. Jour, of Psy., April, 
1893, Vol. 5, pp. 294-310. 

Ehythm. Ibid., Jan., 1894, Vol. 6, pp. 
145-283. 

Asymmetry of Body. Report of Cal. 
State Teachers'' Ass'n, June, 1897. 

Modern Psychology in its Relation to 
Training of Teachers. Ibid., June, 
1897. 

What is the New Psychology and what 
are its Claims ? Teacher and Student, 
San Jos^, Cal., June, 1897, Vol. 4, 
pp. 121-126. 

Knowledge from the Standpoint of Asso- 
ciation. (With E. M. Haskell.) Ed. 
Rev., May, 1898, Vol. 15, pp. 474- 
499. 

Die Zuverlassigkeit einiger Methoden fur 
die Messung des Ermudungsrgades in 
Sohulkindern. Psychol. Arbeiten, 
herausg. v. E. Kraepelin. (In press.) 

OSKAR BOLZA. 

Ph.D., University of Gottingen, 1886; 
Reader in Mathematics, Johns Hopkins 
University, 1888-89 ; Associate in 
Mathematics, Clark University, 1889- 
92 ; Associate Professor of Mathematics, 
University of Chicago, Jan., 1893-Jan., 
1894 ; Professor of Mathematics, ibid., 
Jan., 1894-. 

Author of : — 

Ueher die Reduction Hyperelliptisoher 
Integrale auf EUiptische. Sitzungs- 
berichte der Freiburger Naturforschen- 
den Gesellschaft, 1885. Dissertation, 
Gottingen, 1886. 3Iath. Annalen, 
1887, Vol. 28, pp. 447-456. 

Darstellung der Invarianten der Binar- 
form sechster Ordnung durch die 



Nullwerte der zugehorigen Theta- 
Eunctionen. Ibid., 1887, Vol. 30, pp. 
478-495. 

On Binary Sextics with Linear Transfor- 
mations into Themselves. Am. Jour, 
of Math., 1888, Vol. 10, pp. 47-70. 

On the Construction of Intransitive 
Groups. Ibid., 1889, Vol. 2, pp. 185- 
214. 

On the Theory of Substitution- Groups 
and its Applications to Algebraic Equa- 
tions. Ibid., 1891, Vol. 13, pp. 1-86. 

Ueber Kj'onecker's Definition der Gruppe 
einer Gleiohung. Math. Annalen, 
1893, Vol. 42, pp. 253-256. 

Ueber die linearen Relationen zwisohen 
den zu verschiedenen singularen Punc- 
ten gehorigen Fundamentalsystemen 
von Integralen der Riemaunscheu Dif- 
ferentialgleichung. Ibid., 1893, Vol. 
42, pp. 526-536. 

Netto's Theory of Substitutions, trans- 
lated by Dr. Cole. Bull, of the N. Y. 
Math. Soc, 1893, Vol. 2, pp. 83-106. 

On the Transformation of Linear Differ- 
ential Equations of the Second Order 
with Linear CoefBcients. Am. Jour, 
of Math., 1893, Vol. 15, pp. 264-273. 

On Weierstrass' Systems of Hyperelliptic 
Integrals of the First and Second Kind. 
Chicago 3Iath. Congress Papers, 1893, 
pp. 1-12. 

On the First and Second Logarithmic 
Derivatives of Hyperelliptic Sigma 
Functions. Am. Jour, of Math., 1895, 
Vol. 17, pp. 11-36. 

Die oubische Involution und die Dreithei- 
lung und Transformation dritter Ord- 
nung der EUiptischen Functionen. 
Math. Annalen, 1897, Vol. 50, pp. 
68-102. 

Zur Reduction hyperelliptischen Integrale 
auf elliptisohe mittels einer Transfor- 
mation dritten Grades. Ibid., 1898, 
Vol. 50, pp. 314-324. 

The Partial Differential Equations for the 
Hyperelliptic e — and 5 — Functions. 
Am. Jour, of Math., April, 1899, Vol. 
21, pp. 107-125. 

Proof of Brioschi's Recursion Formula for 
the Expansion of the Even 5 — Func- 



472 



Titles of 



tions of Two "Variables. Am. Jour, of 
Math., April, 1899, Vol. 21, pp. 175- 
190. 

JAMES W. BOYCE: — 

B.S., University of Vermont, 1896; Fel- 
lo-w in Mathematics, Clark Univer- 
Bity, 1896-99. 

■WILLIAM P. BOYNTON: — 

A.B., Dartmouth College (witti honors in 
Physics), 1890 ; Professor of Physics and 
Chemistry, University of Southern Cali- 
fornia, 1890-93 ; A.M., Dartmouth College, 
189.3 ; Graduate Scholar and Assistant 
in Physics, ibid., 1893-94; Scholar in 
Physics, Clark University, 1894-95 ; 
Fellow, 1895-97 ; Ph.D., Clark Uni- 
versity, 1897 ; Instructor in Physics, 
University of California, 1897-. 

Author of : — 

A Quantitative Study of the High-Fre- 
quence Induction-Coil. Physical Be- 
view, July, 1898, Vol. 7, pp. 35-63 ; 
Philosophical Magazine, Sept., 1898, 
5th ser.. Vol. 46, pp. 312-338. 

JOHN L. BRIDGE: — 

B.S., Wesleyan University, Middletown, 
Conn., 1888 ; Assistant in Chemistry, 
ibid., 1889-91 ; FeUow in Chemistry, 
Clark University, 1891-92 ; Fellow in 
Chemistry, University of Chicago, 1892- 
93 ; Ph.D., Clark University, 1894 ; 
Instructor in Sciences, Connecticut Liter- 
ary Institution, 1893-96 ; Instructor in 
Sciences, Waterbury High School, 1896-. 

Author of : — 

The Ethers of Nitroso-phenol. Am. Chem. 
Jour., 1892, Vol. 14, pp. 276-284. 

Ueber die Aether des Chinonoximes. Lie- 
big's Annalen, Vol. 277, pp. 79-105. 

The Ethers of Toluchinonoxime and their 
bearing on the Space Isomerism of 
Nitrogen. (With Wm. Conger Mor- 
gan.) Am. Chem. Jour., Nov., 1898, 
Vol. 20, pp. 761-776. 

CHARLES L. BRISTOL : — 

B.S., New York University, 1883; 
Teacher of Natural Sciences, Riverview 



Academy, Poughkeepsie, N. Y., 1883-87; 
M.S., New York University, 1888 ; Pro- 
fessor of Zoology, State University, 
South Dakota, 1888-91 ; Fellow in 
Morphology, Clark University, 1891- 
92 ; Fellow in Biology, University of 
Chicago, 1892-93 ; Associate Professor of 
Biology, New York University, 1893-98 ; 
Professor of Biology, Ibid., 1898- ; Ph.D., 
University of Chicago, 1894; Member of 
American Naturalists ; Member of Mor- 
phologists' Society ; Member of New York 
Zoological Society ; FeUow of New York 
Academy of Sciences. 

Author of : — 

The Metamerism of Nephelis, a contribu- 
tion to the morphology of the nervous 
system, with a description of Nephelis 
Lateralis. Journal of Morphology, 
Oct., 1898, Vol. 15, pp. 17-72. 

ERNEST NICHOLSON BROWN: — 

B.A., Dalhousie University, Halifax, 
N.S., 1889; Scholar in Psychology, 
Clark University, 1892 ; Assistant in 
Ethnology, World's Columbian Exposi- 
tion, 1893 ; Principal, Model School, 
Levis, Quebec, 1894-95; Principal, Model 
School, Lachine, Quebec, 1895- ; Con- 
vener of Committee on Child Study of 
the Provincial Association of Protestant 
Teachers of Quebec, 1897-. 

Author of : — 

Child Study. Educational Record of the 
Province of Quebec, March, 1898, Vol. 
18, pp. 51-63. 

The Spelling Problem. Ibid. , May-June, 
1899, Vol. 19, pp. 73-92. 

ELMER B. BRYAN: — 

Graduate of Indiana State Normal School, 
1889 ; A.B., Indiana University, 1893 ; 
Principal of High School, Kokomo, Ind., 
1893-94 ; Teacher of History, Industrial 
Training School, Indianapolis, 1894-96 ; 
Professor of Pedagogy, Butler College, 
1896-97 ; Assistant Professor of Peda- 
gogy, Indiana University, 1897-99 ; Asso- 
ciate Professor, 1899- ; Graduate Student 
in Philosophy, Harvard University, Oct., 



Published Papers. 



473 



1898-Jan. , 1899 ; Scholar in Philosophy, 
Clark University, Jan. -June, 1899. 

Author of : — 

School Hygiene. Indiana School Jour- 
nal, July, 1899, Vol. 44, pp. 393-396. 

School Diseases. Ibid., Aug., 1899, Vol. 
44, pp. 465-469. 

The Hygiene of Instruction. Ibid., Sept., 
1899, Vol. 44, pp. 533-536. 

The Care of the Senses. Ibid., Oct., 
1899, Vol. 44, pp. 593-595. 

Child Life. Ibid., Nov., 1899, Vol. 44, 
pp. 647-649. 

•WILLIAM LOWE BRYAN : — 

A.B., Indiana University, 1884; A.M., 
1886 ; Student, University of Berlin, 1886- 
87 ; Instructor in Philosophy, Indiana 
University, 1885 ; Associate Professor in 
Philosophy, ibid., 1885-87 ; Professor in 
Philosophy, ibid., 1887 ; Fellow in Psy- 
chology, Clark University, Oct., 1891- 
Jan., 1893 ; Ph.D., Clark University, 
1892 ; Vice-President, Indiana Univer- 
sity, 1893-. 

Author ot : — 

Pscyhology at Indiana University. Am. 

Jour, of Psy., April, 1890, Vol. 3, pp. 

283-284. 
On the Development of Voluntary Motor 

Ability. Ibid., Nov., 1892, Vol. 5, pp. 

125-204. 
Auditory and Visual Memory in School 

Children. Froc. Internal. Ed. Ass''n, 

1893. 
Suggestions on the Study of Children by 

Teachers. Pamphlet, 8 pp. 
Child Study : Systematic and Unsystem- 
atic. Froc. Dept. of Supt., 1895. 

Proc. N. E. A., 1895, pp. 412-418. 
On the Methods and Results of Child 

Study. Article in Johnson's Encyclo- 

pcedia. 
Syllabus on Imitation of Teacher by Pupil. 

(With U.J. Griffith.) Handb. HI. Soc. 

for Child Study, May, 1895, Vol 1, 

pp. 44-45. 
Science and Education. Froc. N. E. A., 

1895, pp. 161-165. 



Report on Work in Child Study in Indi- 
ana. Ibid., 1895, pp. 905-906. 

Scientific and Non-Scientific Methods of 
Child Study. Ibid., 1896, pp. 856-860. 

Studies on the Physiology and Psychology 
of the Telegraphic Language. (With 
Noble Harter.) Psychological Peview, 
Jan., 1897, Vol. 4, pp. 27-53. 

Hygiene of Motor Development. Froc. 
Dept. of Supt, iV. E. A., 1897. 

Report of Special Committee on the Or- 
ganization of a Committee on School 
Hygiene. National Council of Educa- 
tion, 1897. 

Plato the Teacher. Being Selections from 
the Apology, Euthydemus, Protagoras, 
Symposium, Phsedrus, Republic, and 
Phsedo of Plato. Edited with Intro- 
duction and Notes. (With Charlotte 
Lowe Bryan.) Charles Soribner's 
Sons, New York, 1897. xli. -1- 454 pp. 

The Republic of Plato. With Studies 
for Teachers (with Charlotte Lowe 
Bryan). Charles Scribner's Sons, New 
York, 1898. 313 pp. 

Studies on the Telegraphic Language. 
The Acquisition of a Hierarchy of 
Habits. (With Noble Harter.) Psy- 
chological Pevieio, July, 1899. Vol. 
6, pp. 345-375. 

WARREN G. BULLARD: — 

A.B., Brown University, 1892; Instruc- 
tor in Mathematics, Free Academy, 
Elmira, N.Y., 1892-93; Scholar in 
Mathematics, Clark University, 1893- 
96; Ph.D., Clark University, 1896; 
Instructor in Mathematics, University of 
Vermont, 1896- ; Member of the Ameri- 
can Mathematical Society. 

Author of : — 

On the General Classification of Plane 
Quartic Curves. Math. Peview, Vol. 
I., pp. 193-208. (Preprint.) 

HERMON C. BUMPUS : — 

Ph.B., Brown University, 1884; Instruc- 
tor in Zoology, ibid., 1885-86; Professor 
in Zoology and Geology, Olivet College, 
1886-89 ; Fellow in Animal Morphol- 



474 



Titles of 



ogy, Clark University, 1889-90 ; Ph.D., 
Clark University, 1891 ; Assistant Pro- 
fessor, 1890-91, and Associate Professor 
of Zoology, Brown University, 1891-92 ; 
Professor of Comparative Anatomy, ibid., 
1892- ; Assistant Director, Marine Bio- 
logical Laboratory, Woods HoU, Mass., 
1893-95 ; Director Biological Laboratory 
of the U. S. Fish Commission, 1898- ; 
Secretary of the American Society of Natu- 
ralists, 1895-99 ; Vice-President American 
Society of Naturalists, 1899-. 

Author of : — 

Studies in Zoology. Am. Teacher, 1886. 
Keptiles and Batrachians of Rhode Island. 

Random Notes on Nat. Hist., 1885-86, 

Vols. 2, 3. 
Keptilia. Stand. Nat. Hist., 1885, Vol. 3. 
An Inexpensive Self-registering Anxan- 

ometer. Bat. Gaz., 1887, Vol. 12. 
The Embryology of the American Lob- 
ster. Jour, of Morph. , 1891, Vol. 5, 

pp. 215-262. 
A New Method of using Celloidin for 

Serial Section Cutting. Amer. Nat., 

Jan., 1892, Vol. 26, pp. 80-81. 
A Laboratory Course in Invertebrate 

Zoology. Henry Holt & Co., 1893. 

157 pp. 
The Median Eye of Adult Crustacea. 

Zool. Anz., 1894, p. 447. 
Laboratory Teaching of Large Classes in 

Zoology. Science, March 8, 1895, 

N. S., Vol 1, pp. 260-263. 
Instinct and Education in Birds. Ibid., 

August 21, 1896, N. S., Vol. 4, pp. 213- 

217. 
Report of the Fourteenth Annual Meeting 

of the American Society of Naturalists. 

Ibid., Feb. 28, 1896, N. S., Vol. 3, pp. 

297-299. 
A. Review of " The American Lobster, a 

Study of its Habits and Development," 

by F. H. Herrick. Ibid., Oct. 9, 1896, 

N. S., Vol. 4, pp. 5.36-537. 
A Contribution to the Study of Variation. 

Jour, of Morph., Feb. 1897, Vol. 12, 

pp. 455-484. 
Records of the American Society of 

Naturalists for the Meeting of 1896. 



A Review of Lloyd Morgan's " Habit and 
Instinct." Science, Dec. 17, 1897, 
N. S., Vol. 6, pp. 918-920. 

Report of the Fifteenth Annual Meeting 
of the American Society of Naturalists. 
Ibid., Jan. 7, 1898, N. S., Vol. 7, pp. 
21-23. 

The Result of the Suspension of Natural 
Selection as illustrated by the Intro- 
duced English Sparrow. Ibid., March 
12, 1897, N. S., Vol. 6, pp. 423-424. 

A Recent Variety of the Flatfish, and ita 
Bearing upon the Question of Discon- 
tinuous Variation. Ibid., Feb. 11, 1898, 
N. S., Vol. 7, pp. 197-198. 

Certain Results from a Study of the Varia- 
tion of Littorina. Ibid., Feb. 11, 1898, 
N. S., Vol. 7, p. 198. 

The Breeding of Animals at Woods HoU 
during the Month of March, 1898, 
Science, April 8, 1898, N. S., Vol. 7, 
pp. 485-487. 

The Breeding of Animals at Woods Holl 
during the Month of May, 1898. Ibid, 
July 15, 1898, N. S., Vol. 8, pp. 58-61, 

The Breeding of Animals at Woods Holl 
during the Months of June, July, and 
August, 1898. Ibid. Dec. 16, 1898, 
N. S., Vol. 8, pp. 850-858. 

The Variations and Mutations of the 
Introduced Sparrow (Passer domesti- 
cus). Biological Lectures of the Ma- 
rine Biological Laboratory. 1896-97. 
Ginn & Co., Boston, 1898, pp. 1-15. 

The Variations and Mutations of the In- 
troduced Littorina. Zoological Bul- 
letin, Feb., 1898, Vol. 1, pp. 247-259. 

A Possible Case of Mutation. Jour. Bos- 
ton Soc. Med. Sci., Dec. 21, 1897, 
Vol. 2, pp. 25-26. 

The Work of the Biological Laboratory of 
the U. S. Fish Commission at Woods 
Holl. Science, July 22, 1898, N. S., 
Vol. 8, p. 96. 

The Identification of Adult Fish that have 
been Artificially hatched. Proceed- 
ings American Fisheries Society for 
1898. American Naturalist, June, 
1898, Vol. 32, pp. 407-412. 

Professor James Ingraham Peck. (An 
Account of his Life and Work.) Sci- 



Published Papers. 



475 



ence, Dec. 2, 1898, N. S., Vol. 8, p. 

783. 
The Elimination of the Unfit as illustrated 

by the Introduced Sparrow (Passer 

domesticus) . Biological Lectures of 

the Marine Biological Laboratory. (In 

press.) 
The Return of the Tilefish. Bulletin U. 8. 

Fish Commission. (In press.) 

FHEDERIC BURK: — 

B.L., University of California, 1883; 
Instructor in Literature and History, 
California Military Academy, 1889-90 ; 
Graduate Student in Literature, Univer- 
sity of California, 1890-91 ; Instructor in 
Mathematics, Berkeley Gymnasium, 1890- 
91 ; Graduate Student in Philosophy, Stan- 
ford University, 1891-92, and A. M. , 1892 ; 
Supervising Principal of Schools, Santa 
Rosa, Cal., 1892-96; Fellow in Psy- 
chology, Clark University, 1896-97 ; 
Honorary Fellow, 1897-98; Ph. D., 
Clark University, 1898; Supt. of 
Schools, Santa Barbara, Cal., 1898-99; 
President, State Normal School, San 
Francisco, 1899- ; President of the Cal. 
State Teachers' Ass'n, 1899 ; Chairman of 
the Department of Child Study of the N. 
E. A., 1899. 

Author of : — 

Magic Wand. (Alumni Address at Stan- 
ford University, 1894, pamphlet). 

Report upon the Pedagogical Methods 
in the Schools of Santa Rosa (pam- 
phlet), 1894. 

Modern Changes in Superintendenoy. 
Pacific Ed. Jour., March and April, 
1895. 

Teasing and Bullying. Pedagogical 
Seminary, AprU, 1897, Vol. 4, pp. 
336-371. 

The Training of Teachers; "The Old 
View of Childhood and the New." 
Atlantic Monthly, Oct., 1897, Vol. 80, 
pp. 547-561. 

The Graded System vs. Individual Pupils. 
Northwestern Monthly, March, 1898, 
Vol. 8, pp. 481-484. 

Growth of Children in Height and Weight. 



Am. Jour, of Psy., April, 1898, Vol. 
9, pp. 253-326. 
Normal Schools and the Training of 
Teachers. Atlantic Monthly, June, 

1898, Vol. 81, pp. 769-779. 

From Fundamental to Accessory in the 
Development of the Nervous System 
and of Movements. Pedagogical Sem- 
inary, Oct., 1898, Vol. 6, pp. 5-64. 

The Evolution of Music and the Pedagogi- 
cal Application. Proc. Cal. Teachers^ 
Ass'n, 1898. 

A Curriculum for the Kindergarten from 
a Child's Standpoint. Ibid., 1898. 

A Study of the Kindergarten Problem. 
(With Caroline Frear Burk.) The 
Whitaker and Ray Co., San Francisco, 

1899. 123 pp. 

The Kindergarten Child Physically. 
Proc. N. E. A., 1899. 

Child Study Application to the Curricula 
of the Primary School and Kinder- 
garten. Ibid., 1899. 

The Influence of Exercise upon Growth. 
Am. Phys. Ed. Bev., Dec, 1899, Vol. 
4, and Pro. N. E. A., 1899. 

V7ILLIAM H. BURNHAM : — 

A.B., Harvard University (with Honors 
in Philosophy), 1882 ; Instructor in Witen- 
berg College, 1882-83 ; Instructor in State 
Normal School, Potsdam, N. Y., 1883-85; 
Fellow, Johns Hopkins University, 1885- 
86 ; Ph.D., Johns Hopkins University, 
1888; Instructor in Psychology, ibid., 
1888-89; Docent in Pedagogy, Clark 
University, 1890-92 ; Instructor, 
1892- ; Member of American Psycho- 
logical Association. 

Author of : — 

Memory, Historically and Experimentally 
Considered. I. The Older Conceptions 
of Memory ; II. Modern Conceptions 
of Memory ; III. Paramnesia ; IV. Re- 
cent Theories. Am. Jour, of Psy., Nov., 
1888, Feb., May, Aug., 1889, Vol. 2, 
pp. 39-90 ; 225-270 ; 431-464 ; 568-622. 

The Stage and the Pulpit. Christian 
Union, April 19, 1888, Vol. 37, pp. 
486-487. 



476 



Titles of 



Training the Memory. Nation^ Dec. 13, 
1888, Vol. 47, pp. 480-481. 

Economy in Intellectual Work. Scribner's 
Magazine, March, 1889, Vol. 5, pp. 
306-314. 

Examination and Education. Nineteenth 
Century, Am. Suppl., March, 1889, 
Vol. 25, pp. 32-35. 

Recent Educational Literature. Nation, 
Aug. 15, 1889, Vol. 49, pp. 132-133. 

The New German School. Pedagogical 
Seminary, Jan., 1891, Vol. 1, pp. 13-18. 

The Study of Adolescence. Ibid., June, 
1891, Vol. 1, pp. 174-195. 

Observation of Children at the Worcester 
Normal School. Ibid., June, 1891, 
Vol. 1, pp. 219-223. 

Higher Pedagogical Seminaries in Ger- 
many. Ibid., Dec. 1891, Vol. 1, pp. 
390-408. 

Illusions of Memory. Scribner's Maga- 
zine, Eeb., 1892, Vol. 11, pp. 185-195. 

Outlines of School Hygiene. Pedagogical 
Seminary, June, 1892, Vol. 2, pp. 9-71. 

La nuova scuola tedesca. (Translation 
of " The New German School " by 
Paolo Veochia). Saggi Pedagogici, 
Turin, 1893, pp. 12.3-129. 

A Scheme of Classification for Child-study. 
Pedagogical Seminary, March, 1893, 
Vol. 2, pp. 191-198. 

Individual Differences in the Imagination 
of Children. Ibid., pp. 204-225. 

Some Recent German Literature on Physi- 
cal Education. Ibid., pp. 282-298. 

Child-study as the Basis of Pedagogy. 
Proc. Int. Cong, of Ed., Chicago, 
1893, pp. 718-720. 

Motor Ability in Children : Development 
and Training. Proc. Am. Inst, of 
Instruction, Boston, 1894, pp. 127-140. 

Un esquema de classificaci(5n para el 
estudio del nino. (Translation of 
"A Scheme of Classification for Child- 
study). Boletin de la Institucidn Libre 
de Ensenanza, Madrid, April 30, 1894, 
Vol. 18, pp. 107-112. 

Bibliographical Notes to Lectures in School 
Hygiene. Worcester, Mass., 1897. 
11pp. 

Impurities in the Air of Schoolrooms. 



Northwestern Monthly, July, 1897, 
Vol. 8, pp. 75-80. 

Suggestions from the Psychology of Ado- 
lescence. School Review, Dec. 1897, 
Vol. 5, pp. 14-27. 

Some Aspects of the Teaching Profession. 
The Forum, June, 1898, Vol. 25, pp. 
481-495. 

Bibliography of School Hygiene. Proc. 
N. E. A., 1898, pp. 505-523. 

El estudio del niilo oomo base de la peda- 
gogfa. (Translation of "Child-study 
as the Basis of Pedagogy " by Manuel 
Valdes Rodriguez). Ensayos sobre 
Educacion Te6rica Practica y Experi- 
mental, Tomo Secunda, Habana, 1898, 
pp. 159-162. 

Mental Hygiene. Johnson's Universal 
Cyclopcedia, New Edition, 1C99, Vol. 
10. 

School Diseases. Ibid. 

School Hygiene. Ibid. 

The Child in Education. Nation, Jan. 26, 
1899, Vol. 68, pp. 72-73. 

B. C. BURT: — 

A.B., University of Michigan, 1875 ; Pro- 
fessor, Indiana State Normal School, 1875- 
78 ; A.M., University of Michigan, 1879 ; 
Fellow in Philosophy, Johns Hopkins 
University, 1881 ; Assistant Professor, 
University of Michigan, 1881-87 ; Fellow 
by Courtesy, Johns Hopkins University, 
1887 ; Decent in Philosophy, Clark 
University, 1889-90 ; Ph.D., University 
of Michigan, 1894 ; Professsor (ad in- 
terim) of Philosophy and Pedagogy, 
University of Colorado, 1894-95 ; Agent, 
' ' Northwestern Line " and " Santa F6 
Route," Superior, Nebraska, 1896-. 

Author of : — 

Shakespeare in the Opinion of the 17th 
Century. New Englander, 1881. 

Watson's Kant and his English Critics. 
Unitarian Beview, 1882. 

Series of Articles on Greek Philosophy. 
Unity, Chicago, 1885-86. 

Some Relations between Philosophy and 
Literature. Pub. of Phil. Sac, Uni- 
versity of Michigan, 1886. 



Published Papers. 



477 



References for Students in English Litera- 
ture. Pamplilet, 1887. 
Philosophical Works of Professor George 

S. Morris. Chronicle, 1889. 
A Brief History of Greek Philosophy. 

Ginn & Co., Boston, 1889. xiv. + 296 

pp. 
Translation of Erdmann's History of 

Philosophy from Kant to Hegel. 

Swan, Sonnenschein & Co., London. 
German Philosophy since Hegel. Educa- 
tion, April and May, 1890. 
Natural Science and the Philosophy of 

Nature. Philosophical Beview, May, 

1892, Vol. 1, pp. 284-291. 
History of Modern Philosophy. 2 vols. 

McClurg & Co., Chicago, 1892, 368, 

321 pp. 
Translation of Hegel's Rechts-Pflichten 

und Religionslehre. 
Translation of Erdmann's Logik und 

Metaphysik. Macmillau & Co., New 

York. 

JOHN CREAN CAHDWELL: — 

M.D., University of the City of New York, 
Medical Department, 1888 ; Assistant in 
the Physiological Laboratory, ibid., 1888- 
89 ; Fellovir in Physiology, Clark Uni- 
versity, 1889-91 ; Instructor in Physi- 
ology, Harvard Medical School, 1891-93 ; 
Lecturer on Physiology, Brooklyn College 
of Pharmacy, 1894-98 ; Assistant to the 
Chair of Nervous Diseases, Long Island 
College Hospital, 1897- ; Chief of Clinic 
for Nervous Diseases, Polhemus Clinic, 
Brooklyn, N. Y., 1898- ; Demonstrator of 
Physiology, Long Island College Hospital, 
1899- ; Associate Director of Department 
of Physiology, Hoagland Laboratory, 
1899-. 

ALEXANDER F. CHAMBERLAIN : — 
A.B., University of Toronto (with Honors 
in Modern Languages and Ethnology), 
1886 ; A.M., University of Toronto, 1889 ; 
Fellow in Modern Languages, University 
College, Toronto, 1887-90 ; Examiner in 
French and German, Department of Ed- 
ucation, Toronto, 1888-89; Librarian 
Canadian Institute, Toronto, 1889-90 ; 



Examiner in German, University of To- 
ronto, 1888-91 ; Examiner in Modern 
Languages, Trinity University, Toronto, 
1890-91 ; Anthropological Researches in 
British Columbia, under the auspices of 
the British Association for the Advance- 
ment of Science, Summer of 1891 ; Secre- 
tary Anthropological Section, American 
Association for the Advancement of Sci- 
ence, 1894 ; Secretary Anthropological 
Section, British Association for the Ad- 
vancement of Science, 1897 ; FellovT- 
in Anthropology, Clark University, 
1890-92 ; Ph.D., Clark University, 
1892 ; Lecturer in Anthropology, 
1892-. 

Author of : — 

The Relationship of the American Lan- 
guages. Froc. Canad. Inst. (Toronto), 
3d ser.. Vol. 5, 1886-87, pp. 57-76. 

Prehistoric Ethnology. [Brief Abstract.] 
Ibid., Vol. 5, 1886-87, p. 144. 

The Catawba Language. [Abstract.] 
Ibid., Vol. 6, 1887-88, p. 26. 

The Eskimo Race and Language. Ibid., 
Vol. 6, 1887-88, pp. 261-3.37. 

A First Contribution to the Bibliography 
of the Archeeology of the Dominion of 
Canada and Newfoundland. Ann. 
Bep. Canad. Inst., 1887-88, pp. 54- 
59. 

The Catawba Language. Toronto, 1888. 
4 pp., 8vo. 

The Mississaguas of Scugog. [Abstract.] 
Froc. Canad. Inst., 3d ser.. Vol. 7, 
1888-89, pp. 2-3. 

Deluge Myths of Canadian Indians. [Ab- 
stract.] Ibid., pp. 11-12. 

Archaeology of Scugog Island. [Abstract.] 
Ibid., pp. 14-15. 

The Language of the Mississaguas of 
Scugog. [Abstract.] Ibid., pp. 213- 
215. 

The Origin and Development of Gram- 
matical Gender. [Abstract.] Ibid., 
pp. 216-217. 

A Second Contribution to the Bibliography 
of the Archaeology of Canada. Ann. 
Bep. Canad. Inst., 1888-89, pp. 102- 
118. 



478 



Titles of 



Notes on the Negro Words lagniappe, 
buccra, goober. Science, July 13, 1888, 
p. 23. 

Mississagua Etymology. Ibid., Sept. 14, 
p. 132. 

The Archseology of Scugog Island. Port 
Perry, 1889. 4 pp., 8vo. 

Notes on the History, Customs, and Be- 
liefs of the Mississagua Indians. Jour. 
Am. Folk-Lore, Vol. 1, 1888, pp. 150- 
160. 

Tales of the Mississaguas. I. Ibid. , Vol. 

2, pp. 141-147. 

A Mohawk Legend of Adam and Eve. 
Ibid., Vol. 2, pp. 228, 311. 

Algonkin Onomatology, with some Com- 
parisons with Basque. [Abstract.] 
Proc. Am. Ass'n Adv. Sci., Vol. 38, 
1889, pp. 351-352. 

The Two Brothers : A Mississagua Leg- 
end. [Abstract.] /6W., pp. 352-353. 

"Words of Indian Origin in the French 
Canadian Dialect and Literatiire. Am. 
Notes and Queries (Philadelphia), Vol. 
1, 1888, pp. 220-221, 232-233, 258-259, 
270-271, 278-279, 293-294, 305-306; 
Vol. 2, 1888-89, pp. 2-3, 16-17, 30-31, 
52-53, 62-63, 76-77, 87-88, 99-100, 
124-125 ; Vol. 4, 1889, pp. 77-78. 

Who was "Etowokoam," mentioned in 
Spectator, No. 50 ? Ibid., Vol. 2, pp. 
287-288. 

The Etymology of Terrapin. Ibid., Vol. 

3, pp. 210-211. 

The Etymology of Tucquan. Ibid., Vol. 

3, pp. 262-263 ; Vol. 4, p. 324. 
The Derivation of Chicago. Ibid., Vol. 4, 

pp. 36, 91-92. 
The Names of the Humming Bird. Ibid. , 

Vol. 4, pp. 206-208. 
New York Dialect Forms. Ibid. , Vol. 3, 

pp. 295-296. 
Slav Proverbs. ' Varsity (University of 

Toronto), April 7, 1888. 
Etymology of Horse-Radish. Am. Notes 

and Queries, Vol. 2, 1889, pp. 119-120. 
Etymologies of Acadia, gore, undern, 

goober, Saginaw, Key West, cockle. 

Gal, elfetrich, Manhattan, moonack, 

hurrah, chipmunk, plaquemine. Ibid., 

Vol. 1, p. 285 ; Vol. 2, pp. 69, 310, 311 ; 



Vol. 3, pp. 8, 9, 10, 103, 107 ; Vol. 4, pp 

34, 164, 155, 214. 
Hiawatha in Flemish. Ibid. , Vol. 3, pp, 

85-87. 
Etymology of Fad. Ibid., Vol. 3, pp 

154-155. 
Mississagua Place Names. Jour. Am. 

Folk-Lore, Vol. 3, 1890, p. 74. 
Tales of the Mississaguas. U. Ibid., pp, 

149-154. 
A Negro Creation Legend. Ibid. , p. 302, 
The Indians of Canada. [Abstract.] 

Trans. Canad. Inst., Vol. 1, 1890-91 

pp. 18-19. 
The American Indian in Literature. [Ab- 
stract.] Ibid., pp. 33-34. 
Mohawk Folk-Lore. Science, Vol. 16, 

1890, p. 289. 
The Prehistoric Naturalist. Univ. Quart. 

Bev. (University of Toronto), Vol. 1, 

1890, pp. 179-197. 
Dialect Research in Canada. Dialect 

Notes, Vol. 1, 1890, pp. 43-56. 
Contributions toward a Bibliography of 

the Archaeology of the Dominion of 

Canada and Nevrfoundland. III. Ann. 

Hep. Canad. Inst., 1890-91, pp. 78-82. 
The Algonkian Indians of Baptiste Lake. 

Ibid., pp. 83-89. 
The Aryan Element in Indian Dialects. I. 

Canadian Indian, Vol. 1, 1890-91, 

pp. 148-153. 
The Thunder-Bird amongst the Algonkins. 

American Anthropologist, Vol. 3, 1890, 

pp. 51-54. 
Note on the Os Iuceb. Ibid., Vol. 3, p. 

104. 
Notes on Indian Child Language. Ibid., 

Vol. 3, pp. 237-241. 
The Maple amongst the Algonkian Tribes. 

Ibid., Vol. 4, 1891, pp. 39-43. 
Maple Sugar and the Indians. Ibid., 

Vol. 4, pp. 381-383. 
Folk-Etymology in Canadian French. 

Modern Language Notes, Vol. 6, 1891, 

202-205. 
Notes of French Canadian Folk-Lore. 

Dominion Illustrated (Montreal), Vol. 

4, 1891, pp. 12-13. 
Nanibozhu amongst the Otchipw^, Mis- 

sissagas, and other Algonkian Tribes. 



Published Papers. 



479 



Jour. Am. Folk-Lore, Vol. 4, 1891, 
pp. 193-213. 

Words of Algonkian Origin in the Chinook 
Jargon. Science, Vol. 18, 1891, pp. 
260-261. 

African and American. The Contact of 
the Negro and the Indian. Ibid., Vol. 
17, 1891, pp. 85-90. 

Classics and Modern Languages in Europe 
and America since 1880, or Ten Years 
of the New Learning. Toronto, 1891, 
60 pp. 

Some Points in Linguistic Psychology. 
Am. Jour, of Psy., Vol. 5, 1892-93, 
pp. 116-119. 

Notes on the Canadian French Dialect of 
Granby, P. Q. I. Vocabulary. Mod- 
ern Language Notes, Vol. 7, 1892, pp. 
324-327. 

Der Wettlauf: Eine Sage der Kftonaqa. 
Am Ur-Quell, III. Bd., 1892, S. 212- 
213. 

A Mississaga Legend of Nanlbozhu. Jour. 
Am. Folk-Lore, Vol. 6, 1892, pp. 291- 
292. 

The Use of Diminutives in -ing by Some 
Writers in Low German Dialects. 
Pub. 3Iod. Lang. Ass'n Am., Vol. 7 
1892, pp. 212-217. 

The Language of the Mississagas of 
Skiigog. A Contribution to the Lin- 
guistics of the Algonkian Tribes of 
Canada. [Thesis.] Philadelphia, 1892. 
84 pp., 8vo. 

British Association for the Advancement 
of Science. Edinburgh Meeting, 1892. 
Eighth Report on the Northwestern 
Tribes of Canada. Report on the 
Kootenay Indians of Southeastern 
British Columbia. (With introduc- 
tion by Horatio Hale.) London, 1892. 
71 pp., 8vo. 

Human Physiognomy and Physical Char- 
acteristics in Folk-Lore and Eolk- 
Speech. Jour. Am. Folk-Lore, Vol. 
6, 1893, pp. 13-24. 

The Canadian-French Dialect of Granby, 
Province of Quebec. II. Phonetics. 
Modern Language Notes, Vol. 8, 1893, 
31-35. 

Einige Wurzeln aus der Sprache der Ki- 



touaqa^Indianer von Britisch-Colum- 
bien. Verh. der Berl. Gesellsch. f. 
Anthr., Ethn. u. Urgesch., 1893, S. 
419-425. 

TJeber den Zauber mit menschliohem Blut 
und dessen Ceremonial-Gebrauch bei 
den Indianem Amerikas. Am Ur- 
Quell, IV. Bd., 1893, I., S. 1-3, IL, S. 
34-37, III., S. 64-65. 

Sagen vom Ursprung der Fliegen und 
Moskiten. Ibid., S. 201-202. 

Die Natur und die Naturerscheinungen in 
der Mythologie und Volkkunde der In- 
dianer Amerikas. I. Der. Regenbo- 
gen. Ibid., S. 261-262. 

The Physical Education of Woman. By 
Prof. Mosso. [Translation.] Peda- 
gogical Seminary, Vol. 2, 1892-93, pp. 
226-235. 

Notes on the Kootenay Indians. I. The 
Name. Am. Antiq. and Orient. Jour., 
Vol. 15, 1893, pp. 292-294. 

Further Notes on Indian Child Language. 
American Anthropologist, Vol. 6, 1893, 
pp. 321-322. 

Colour-Comparisons in the Low-German 
Poets. [Abstract.] Trans. Canad. 
Inst., Vol. 3, 1892-93, pp. 43-44. 

"Ch'nai-Sny." Nation, Vol. 56, p. 82. 

Sulle significazioni nella lingua degli in- 
digeni americani detti Kftonaqa (Koo- 
tenay) dei termini che denotano gli 
stati e le condizioni del corpo e dell' 
animo. Saggio di psicologia filologica. 
Arch, per V antrop. e la etnol. Firenze, 
Vol. 23, 1893, pp. 393-399. 

Primitive Woman as Poet. [Abstract.] 
Proc. Am. Ass''n Adv. Sci., Vol. 42, 
1893, p. 317. 

Syllabus of Lectures on the Mythology of 
the North American Indians. Report 
of President Clark Univ., 1893, pp. 
123-125. 

Bibliography to accompany a Syllabus of 
Lectures on the Mythology of the 
North American Indians. Ibid., pp. 
141-158. 

The Coyote and the Owl (Tales of the 
Kootenay Indians). Mem. Intern. 
Cong. Anthrop., Chicago, 1894, pp. 
282-284. 



480 



Titles of 



A Kootenay Legend : The Coyote and the 
Mountain Spirit. Jour. Am. Folk- 
Lore, Vol. 7, 1894, p. 195. 

Words Expressive of Cries and Noises in 
the Kootenay Language. American 
Anthropologist, Vol. 7, 1894, pp. 68- 
70. 

New Words in the Kootenay Language. 
Ibid., pp. 186-192. 

Life and Growth of Words in the French 
Dialect of Canada. I. Modern Lan- 
guage Notes (Baltimore), Vol. 9, 1894, 
pp. 78-87. 

Life and Growth of Words in the French 
Dialect of Canada. II. Ibid., pp. 
135-141. 

Ueber die Benennung des Pferdes in den 
Sprachen amerikanischer Indianer. 
Am Ur-Quell, V. Bd., 1894, S. 5-6. 

Notes on the Kootenay Indians. Second 
Paper. Linguistic Data. American 
Antiq., Vol. 17, 1894, pp. 271-274. 

Anthropology in Universities and Colleges. 
Pedagogical Seminary, Vol. 3, Oct., 
1894, pp. 48-60. 

Primitive Anthropometry and its Folk- 
Lore. [Abstract.] Proc. Am. Ass^n 
Adv. Sci., Vol. 43, 1894, pp. 348-349. 

Incorporation in the Kootenay Language. 
[Abstract.] Ibid., pp. 346-348. 

Translation into Primitive Languages ; 
Errors and Pitfalls ; with illustrations 
from Algonkian dialects. [Abstract.] 
Ibid., p. 346. 

Bayou (Etymology). Nation, Nov. 22, 
1894, Vol. 69, p. 381. 

La Belle Nivernaise, par Alphonse Daudet, 
and Le Chien du Capitaine, par Louis 
;fenault. Edited, with Lives of the 
Authors, Notes, and Vocabulary, by 
John Squair, B.A., and A. F. Cham- 
berlain, M.A. Toronto, 1890, 6 + 
184, and 198 + 132 pp. 

Notes on the Kootenay Indians. III. 
Mythology and Folk-Lore. Am. An- 
tiq. and Orient. Jour., Vol. 17, 1895, 
pp. 68-72. 

On Words for "Anger" in Certain Lan- 
guages. A Study in Linguistic Psy- 
chology. Am. Jour, of Psy., Vol. 6, 
1894-95, pp. 585-592. 



Mutation of Gender in the French Dialect 

of Canada. Modern Language Notes, 

Vol. 10, pp. 232-236. 
The Child and Childhood in Folk-Thought 

(The Child in Primitive Culture) _ 

Macmillan's, N. Y., 1896, x. + 474 pp., 

8vo. 
Indian Legends and Beliefs about the 

Squirrel and the Chipmunk. Jour. 

Am. Folk-Lore, Vol. 9, 1896, pp. 48- 

50. 
The Poetry of American Aboriginal 

Speech. Ibid., pp. 43-47. 
Record of American Folk-Lore. Ibid., 

pp. 204-209. 
Beitrag zur Pflanzenkunde der Naturvolker 

America's. Verh. d. Berl. Ges. f. 

Anthr., 1895, S. 551-556. 
Childhood. Address before Conference of 

Lend-a^Hand Clubs, Lowell, Mass., 

Feb. 1, 1896. Ten Times One Record 

(Boston), Vol. 3, 1896, pp. 7-8. 
Anthropology at the Toronto Meeting of 

the British Association. Science, N. 

S., Vol. 6, 1897, pp. 575-583. 
Record of American Folk-Lore. Jour. 

Am. Folk-Lore, Vol. 10, 1897, pp. 

67-75. 
In Memoriam : Horatio Hale. Ibid., pp. 

60-66. 
The Mythology and Folk-Lore of Inven- 
tion. 7ft lU, pp. 89-100. 
Record of American Folk-Lore. Ibid., 

pp. 149-154. 
The Unitarian Church as a Social Institu- 
tion versus Alcoholism. Boston, 1897, 

15 pp. 
The Lesson of the " Little Child." North- 

xoestern Monthly (Lincoln, Neb.), Vol. 

7, 1898, pp. 435-439. 
Record of American Folk-Lore. Jour. 

Am. Folk-Lore, Vol. 10, 1897, pp. 

233-239. 
Darwin and Lincoln. An Anniversary 

Address. Worcester (Mass.) Gazette, 

Feb. 8, 1898. 
Record of American Folk-Lore. Jour. 

Am. Folk-Lore, Vol. 11, 1898, pp. 

61-66. 
The Kootenays and their Salishan Neigh- 
bours. Pep. Brit. Ass^n Adv. Sci. 



Published Papers. 



481 



(Toronto, 1897), Vol. 47, London, 
1898, p. 792. 

Kootenay Indian Drawings. Ibid., pp. 
797-798. 

Eecord of American Folk-Lore. (Jointly 
with I. C. C.) Jour. Am. Folk-Lore, 
Vol. 11, 1898, pp. 151-158. 

Eecord of American Folk-Lore. (Jointly 
with I. C. C.) Ibid., pp. 293-297. 

On the Words for Fear in Certain Lan- 
guages. A Study in Linguistic Psy- 
chology. Am. Jour. Psy., Vol. 10, 
1898-99, pp. 302-305. 

Ethnology of the Aborigines. In British 
Association for the Advancement of 
Science (Toronto Meeting, 1897). 
Handbook of Canada (Toronto, 1897), 
pp. 106-126. 

American Indian Names of White Men 
and Women. Jour. Am,. Folk-Lore, 
Vol. 12, 1899, pp. 24-31. 

The Child. A Study in Human Evolu- 
tion. (Volume of ahout 400 pages. 
In press.) 

Art of the Kootenay Indians. (In prep- 
aration.) 

Mythology of the Kootenays. (In prep- 
aration.) 

Dictionary of the Kootenay Indian Lan- 
guage. I. Kootenay-English. II. Eng- 
lish-Kootenay. (In preparation.) 

Three Shapers of Childhood's Genius — 
Society, Opportunity, Travel. North- 
leestern Monthly, June, 1899, Vol. 9, 
pp. 439-443. 

Eecord of American Folk-Lore. (With 
L C. C.) Jour. Am. Folk-Lore, Vol. 
12, 1899, pp. 136-143. 

Numerous reviews of books and articles in 
Journal of American Folk-Lore, He- 
view of Historical Publications relat- 
ing to Canada, American Journal of 
Psychology, Pedagogical Seminary, etc. 

WILL ORANT CHAMBERS: — 

Graduate, Pennsylvania State Normal 
School, Lock Haven, 1887 ; Instructor in 
Mathematics, ibid., 1887-90 ; A.B., La- 
fayette College (Honors in English and 
Philosophy), 1894 ; Instructor in Mathe- 
matics, State Normal School, Indiana, Pa., 
2i 



1894-97 ; B.S., State Normal School, Indi- 
ana, Pa., 1895 ; M.S., ibid., 1897 ; A.M., 
Lafayette College, 1897 ; Scholar in 
Psychology, Clark University, 1897- 
98 ; Instructor in Mathematics and Peda- 
gogy, State Normal School, Indiana, Pa., 
1899-. 

WALTER CHANNING: — 

Student, Massachusetts Institute of Tech- 
nology, 1867-68 ; M.D., Harvard Univer- 
sity, 1872 ; Honorary Scholar, Clark 
University, 1889-90 ; Honorary Fel- 
low, 1890-92 ; Professor of Mental 
Diseases, Tufts College Medical School, 
1895- ; Assistant Physician Asylum for In- 
sane Criminals, New York, 1873-75 ; First 
Assistant Physician, Insane Hospital, 
Danvers, Mass. 1876-78 ; Superintendent, 
Private Hospital Mental Diseases, Brook- 
line, Mass., 1879- ; Chief, Department 
Mental Diseases, Boston Dispensary ; 
Consulting Physician, Boston Aid Soci- 
ety ; Member of : American Medical Asso- 
ciation, Massachusetts Medical Society, 
American Medico-Psychological Society, 
American Neurological Society, New 
England Psychological Society, Boston 
Medical Improvement Society, Boston 
Medical Library Association, Corporation 
Massachusetts School for Feeble-minded ; 
Honorary Member, Association Institu- 
tions for Feeble-minded ; Member of : 
Council American Association Advance- 
ment Physical Education, Boston Society 
of Physical Education, Massachusetts 
Prison Association, National Conference 
of Charities ; Ex-president, Brookline 
Education Society, and Boston Medico- 
Psychological Society ; Trustee, New Eng- 
land Conservatory of Music ; Member, 
Brookline School Board. 

Author of: — 

Case of Helen Miller. Self-mutilation. 

Tracheotomy. Am. Jour, of Insanity. 
A Case of Feigned Insanity. Boston Med. 

and Surg. Jour., 1878, Vol. 98, p. 655. 
Buildings for Insane Criminals. Proc. of 

Conference of Charities, Chicago, 

June, 1879. 



482 



Titles of 



Care of tlie Insane in Massachusetts. 
Boston Med. and Surg. Jour. 1879, 
Vol. 101, p. 760. 

The Study of Psychological Medicine. 
Ibid., 1880, Vol. 102, p. 315. 

Note on the Construction of Hospitals for 
Insane Paupers. Proc. of Conference 
of Charities, Cleveland, June, 1880. 

Kecent Progress in Insane Asylum Man- 
agement. Boston Med. and Surg. 
Jour., 1880, Vol. 102, p. 243. 

The Treatment of Insanity in its Economic 
Aspect. Proc. of Am. Social Sci. Ass' n, 
Saratoga, N. Y., Sept. 8, 1880. 

The Use of Mechanical Restraint in Insane 
Hospitals. Boston Med. and Surg. 
Jour., 1880, Vol. 103, p. 173. 

Eeoent Progress in Insane Asylum Man- 
agement and Care of the Insane. Ibid., 
1881, Vol. 104, p. 272. 

The Care of Insane Criminals. Ibid., 

1881, Vol. 104, p. 172. 

Medical Expert Testimony. Ibid., 1881, 
Vol. 105, p. 1. 

The Mental Status of Guiteau, the Assassin 
of President Garfield. Ibid., 1882, 
Vol. 106, p. 290. 

Eecent Progress in Insane Asylum Man- 
agement and Construction. Ibid., 

1882, Vol. 106, p. 267. 

Eecent Progress in the Management of 
Lunatic Asylums and Care of the In- 
sane. Ibid., 1882, Vol. 107, p. 441. 

Non-Eestraint in Lunatic Asylums. Ibid., 

1882, Vol. 107, p. 282. 

Medical Treatment of the Insane with 
Special Reference to Opium. Ibid., 

1883, Vol. 108, p. 86. 

Eeport on Recent Progress in the Con- 
struction of Insane Hospitals and 
Management of the Insane. Ibid., 
1883, Vol. 109, p. 462. 

A Consideration of the Causes of Insanity. 
Fifth. Ann. Rep. Mass. Board of 
Sealth, Lunacy, and Charity, 1884. 

Eecent Progress in the Construction of 
Insane Hospitals and Management of 
the Insane. Boston Med. and Surg. 
Jour., 1884, Vol. 110, pp. 295 and 321. 

Eeport on the Care of the Insane. Ibid., 
1885, Vol. 112, p. 342. 



Temperature of the Insane, Especially in 
Acute Mania and Melancholia. Ihid., 

1885, Vol. 113, pp. 1 and 29. 

The Connection between Insanity and 
Crime. Eep. of the Com. on Biblio- 
graphy of Insanity. Proc. of Am. 
Ass'n of Med. Supts. of Am. Institu- 
tions for the Insane, Saratoga, N. Y., 
June, 1885. 

Eecent Progress in the Care of the Insane. 
Boston Med. and Surg. Jour. 1886, 
Vol. 114, pp. 291 and 318. 

Eeport of a Case of Epilepsy of Eorty-flve 
Years' Duration, with Autopsy. Ibid., 

1886, Vol. 115, p. 4. 

Eecent Progress in Care of the Insane. 

Ibid., 1887, Vol. 116, pp. 351-372. 
Progress in the Care of the Insane. Ibid., 

1888, Vol. 118, p. 424. 
An International Classification of Mental 

Diseases. Am. Jour, of Insanity, Jan., 

1888. 
Massachusetts Lunacy Laws. Boston 

Med. and Surg. Jour., 1888, Vol. 119, 

p. 97. 
Lunacy Legislation as Proposed by Dr. 

Stephen Smith and Others. Am. Jour. 

of Insanity, Jan., 1889. 
Physical Training of the Insane. Ibid., 

Oct., 1889. 
Physical Education. Boston Med. and 

Surg. Jour., 1891, Vol. 125, p. 4. 
Physical Education of Children. Proc. of 

the Ann. Meeting of the Social Sci. 

Ass'n, Sept. 1891. 
Evolution of Paranoia. (Eep. of a Case.) 

Jour, of Nervous and Mental Diseases, 

1892, p. 192. 
Some Eemarks on the Address Delivered 

to the American Medico-Psychological 

Association by S. Weir Mitchell, M.D., 

May 16, 1894. Am. Jour, of Insanity, 

Oct. 1894. 
Tuberculosis in Mental Disease. Boston 

Med. and Surg. Jour., 1894, Vol. 131, 

p. 62. 
Physical Training in Childhood. Educa- 
tional Bevieio, Oct., 1895, Vol. 10, pp. 

262-272. 
The Importance of Frequent Observations 

of Temperature in the Diagnosis of 



Published Papers. 



483 



Chronic Tuberculosis. Boston Med. 

and Surg. Jour., Oct. 21, 1895. 
A Case of Tumor of the Thalamus, with 

Remarks on the Mental Symptoms. 

Jour, of Nervous and Mental Diseases, 

Aug., 1896. 
The Significance of the Palatal Deformities 

of Idiots. Jour. Mental Sci., London, 

Jan., 1897. 
Beginnings of an Education Society. 

Educational Review, Nov., 1897. 
Characteristics of Insanity. Boston Med. 

and Surg. Jour., Dec. 9 and 16, 1897. 
The Relation of the Medical Profession to 

School Education. Annals of Gyne- 
cology and Pcediatry, Jan. 26, 1897. 
Physical Ti-aining in the Boston Public 

Schools. Am. Physical Ed. Review, 

June, 1897. 
Medical Expert Testimony in the Kelly 

Murder Trial. Am. Jour, of Insanity, 

No. 3, 1898, Vol. 54. 
The New Massachusetts Board of Insanity. 

Charities Review, Oct., 1898. 

OSCAR CHRISMAN: — 

Teacher and Principal in Public Schools, 
(Owen County, Gosport, Peru, Xenia, 
Logansport), Indiana, 1876-85 ; Graduate, 
Indiana State Normal School, 1887 ; A.B., 
Indiana University, 1888 ; Principal (Third 
"Ward), Public School, Houston, Texas, 
1888-89 ; Supt. Public Schools, Gonzales, 
Texas, 1889-92 ; Fellow in Pedagogy, 
Clark University, 1892-94; A.M., 
Indiana University, 1893 ; Student in 
Philosophy and Pedagogy, University of 
Jena, 1894-95 ; Ph.D., University of Jena, 
1895; Professor of History of Education 
and Child-study, Kansas State Normal 
School, 1896- ; Secretary, 1898, and Presi- 
dent, 1899, of the Kansas Society for 
Child-study. 

Author of : — 

The Hearing of Children. Pedagogical 

Seminary, Dec, 1893, Vol. 2, pp. 397- 

441. 
Secret Language of Children. Science, 

1893, Vol. 22, p. 303 ; 1894, Vol. 23, 

p. 18. 



The Science of the Child. South Dakota 
Educator, Feb., 1894, p. 11. 

Vertical Writing. Texas School Jour., 
1894. 

Child-study, a New Department of Edu- 
cation. Forum, Feb., 1894, Vol. 16, 
pp. 728-736. 

Contribution to a Symposium on Child- 
study. Interstate School Review, 
Illinois, June, 1894, p. 225. 

One Year with a Little Girl. Educational 
Review, Jan., 1895, Vol. 9, pp. 52-71. 

Paidologie, Entwurf zu einer W"issenschaft 
des Kindes. Inaugural-Dissertation 
der philosophischen Fakultat der Uni- 
verstat Jena zur Erlangung der Doktor- 
wfirde. Jena, 1896. 96 pp. 

Children's Secret Language. Child-study 
3Ionthly, Sept., 1896, Vol. 2, pp. 202- 
210. 

How a Story Affected a Child. Ibid., 
April, 1897, Vol. 2, pp. 650-661. 

The Hearing of School Children. North- 
western Monthly, July, 1897, Vol. 8, 
pp. 31-35. 

Motor Control : Its Place in the Physical 
and Psychical Life of the Child. State 
Normal Monthly, Oct., 1897, Vol. 10, 
p. 3. 

Child-study in Texas. Child-study 
Monthly, Nov., 1897, Vol. 3, p. 287. 
(Report of the Child-study Section of 
the Texas State Teachers' Association 
held at Waco, June 29-July 2, 1897.) 

The Secret Language of Children. North- 
western Monthly, Vol. 8, Oct., 1897, 
p. 187 ; June, 1898, p. 649 ; and Jan., 
1899, p. 375. 

Exceptionals. State Normal Monthly, 
Jan., 1898, Vol. 10, p. 51. 

Results of ChUd-study. Education, Feb., 
1898, Vol. 18, pp. 323-332. 

Religious Ideas of a Child. Child-study 
Monthly, March, 1898, Vol. 3, pp. 516- 
528. 

How to use the Library. Western College 
Magazine, March, 1898, Vol. 19, p. 
502. 

Paidology, the Science of the Child. Edu- 
cational Review, March, 1898, Vol. 15, 
pp. 269-284. 



484 



Titles of 



The Secret Language of Childhood. Cen- 
tury, May, 1898, Vol. 56, pp. 54-58. 

Religious Periods of Child-growth. Edu- 
cational Beview, June, 1898, Vol. 16, 
pp. 40-48. 

Child and Parent. Northwestern Monthly, 
Vol. 9, Nov., 1898, p. 135 ; Dec, 1898, 
p. 180. 

The Pubescent Period. Education, Feb., 
1899, Vol. 19, pp. 342-347. 

Opening Remarks as President of the 
Kansas Society for Child-study. Child- 
study Monthly, Feb., 1899, Vol. 4, p. 
451. 

Editorial for the Child-study Department. 
Northwestern Monthly, Feb., 1899, 
Vol. 9, p. 275. 

Child and Teacher. Jour, of Pedagogy, 
May, 1899, Vol. 12, pp. 112-125. 

Courses of Study for Normal Schools. 
Arena, July, 1899. 

ARTHUR L. CLARK: — 

S.B., Worcester Polytechnic Institute, 
1894 ; Instructor in Mathematics and 
Physics, Bridgeton Academy, Me., 1895- 
96 ; Scholar in Physics, Clark Uni- 
versity, 1896-97 ; Fellow, 1897-98 ; 
Instructor in Science, Worcester Academy, 
1898-. 

Author of : — 

A Method of Determining the Angle of 
Lag. Phil. Mag., April, 1896, Vol. 
41, pp. 369-372. 

On the Specific Inductive Capacity of Cer- 
tain Oils. Physical Beview, Feb. , 1898, 
Vol. 6, pp. 120-125. 

ROBERT CLARK:— 

A.B., Amherst College, 1892; Teaching, 
1892-97 ; Scholar, Clark University, 
1897-99. 

THOMAS H. CLARK: — 

B.S., Worcester Polytechnic Institute, 
1880 ; Assistant Superintendent Pennsyl- 
vania Lead Co., 1881-84 ; Student, Johns 
Hopkins University, 1884-85 ; Assistant 
in Chemistry, Wesleyan University, 1886- 
89 ; Fellow in Chemistry, Clark Uni- 
versity, 1889-92 ; Ph.D., Clark Uni- 



versity, 1892 ; Assistant in Chemistry, 
1892-93 ; Instructor in Quantitative 
Analysis, Tufts College, 1894-95; In- 
structor in Chemistry and Physics, Clinton 
Liberal Institute, 1895-97 ; Instructor in 
Chemistry and Physics, State Normal 
School, Plymouth, N. H., 1897- ; Member 
Am. Institute of Mining Engineers, and 
German Chem. Society. 

Author of : — 

The Addition-Products of Benzo- and of 
Toluquinone. Am. Chem. Jour. , Dec, 
1892, Vol. 14, pp. 553-576. 

Relative Leichtigkeit der Kohlendioxyd- 
abspaltung aus den Silbersalzen der 
/3-Chlorcrotonsauren. (With Professor 
Arthur Michael.) Jour, fur prakt. 
Chemie, 1895, N. F., Bd. 52, pp. 326- 
329. 

CHARLES "W. CLINTON: — 

Principal of Public Schools in Wisconsin 
and Minnesota ; County Superintendent, 
Wisconsin ; Visitor to the State Normal 
Schools, Wisconsin ; Professor, Shattuok 
School, Faribault, Minn., 1880-88; Prm- 
cipal, St. John's Military Academy, Kan- 
sas, 1888-90; Head Master, Peekskill 
Military Academy, 1891-93 ; Principal, 
Marmaduke (Mo.) Military Academj', 
1893-94; Ph.D., Ottawa University, 1895; 
Principal, Clinton Classical School, 1895- 
97 ; Fellow in Psychology, Clark 
University, 1897-98 ; Professor of 
Mathematics and Latin, Stamford (Ct.) 
Preparatory School, 1899. 

HERBERT OTIS CLOUQH: — 

A.B., Bowdoin College, 1896; Scholar 
in Mathematics, Clark University, 
1896-97; Assistant in Mathematics, 
Bowdoin College, 1897-98 ; Principal 
Kennebunkport (Me.) High School, 1898-. 

FREDERICK W. COLEGROVE: — 

A.B., Colgate University, 1882; A.M., 
ibid., 1885 ; Student, Hamilton Theological 
Seminary, 1882-84 ; Principal, Collegiate 
Institute, Maiion, N. Y., 1884-89; Pro- 
fessor of Latin, Colgate University, 1889- 
92 ; President, Ottawa University, Kansas, 



Published Papers. 



485 



1892-96; D.D., University of Rochester, 
1893 ; Honorary Fellow^ in Psychology, 
Clark University, 1896-98 ; Ph.D., 
Clark University, 1898 ; Honorary 
Fello-w in Psychology, Oct. -Dec, 
1898 ; Student in Universities of Europe, 
1899 ; Professor of Philosophy, Univer- 
sity of Washington, Seattle, Sept., 1899- ; 
Member of the American Philological 
Association, and Kansas Historical So- 
ciety. 

Author of : — 

Freedom of Worship. Our Young Peo- 
ple, April, 1897. 

Individual Memories. Am. Jour, of Psy., 
Jan., 1899, Vol. 10, pp. 228-255. 

The Time required for Recognition. 
Ibid., pp. 286-292. 

Notes on Mental Standards of Length. 
Hid., pp. 292-295. 

LEVI L. CONANT: — 

A.B., Dartmouth College, 1879; Princi- 
pal of High Schools, Minnesota and 
Indiana, 1880-83; Superintendent of 
Schools, Deadwood and Rapid City, So. 
Dak., 1883-87; A.M., Dartmouth College, 
1887 ; Professor of Mathematics, Dakota 
School of Mines, 1887-90 ; Scholar in 
Mathematics, Clark University, 1890- 
91 ; Assistant Professor of Mathematics, 
Worcester Polytechnic Institute, 1891-92 ; 
A.M. and Ph.D., Syracuse University, 
1893 ; Associate Professor of Mathematics, 
Worcester Polytechnic Institute, 1892-98 ; 
Professor of Mathematics, ibid., 1898-. 

Author of: — 

Historical Development of Arithmetical 
Notation ; and Text Books in Arith- 
metic. Pedagogical Seminary, June, 
1892, Vol. 2, pp. 149-163. 

Primitive Number Systems. Smithsonian 
Report, 1892, pp. 583-594. 

The Teaching of Mathematics. School 
Seview, April, 1893, Vol. 1, pp. 210- 
217. 

Note on the Translation of Certain Me- 
moirs on Infinite Series. Bull, of the 
N.Y. Math. Soc, 1894. 



The Origin of Numeral Words. Proc. A. 
A. A. 8., 1894. 

English Folk Tales in America. Jour, of 
Am. Folk-Lore, April-June, 1895, Vol. 
8, pp. 143-144. 

The Number Concept. Macmillan and 
Company, Nev7 York, 1896. vi. -f- 
218 pp. 

An Application of the Theory of Substi- 
tutions. Am. Math. Soc, Aug., 1898. 

ALFRED COOK:— 

A.B., Northwestern University, 1877; 
Ph.D., University of Halle, 1886 ; Fellow 
by courtesy, Johns Hopkins University, 
1887 ; Superintendent of Schools, Nimonk, 
111., 1887-88; Instructor in Philosophy, 
Bryn Mawr College, 1888-89; Docent 
and Lecturer on History of Philoso- 
phy, Clark University, 1889-90 ; Inde- 
pendent University Extension Lecturer 
on Psychology and on the Philosophy of 
History, 1896-. 

Author of : — 

Ueber die Berkeleysche Philosophie. C. 
A. Kaemmerer & Co., Halle, 1886. 
48 pp. 

Harmony of Natural Law and Free Will, 
a Dissertation on the Kantian Philoso- 
phy. Bloomington, 111., 1888. 16 pp. 

L. P. CRAVENS: — 

A.B., Carthage College, 1878; A.M., 
ibid., 1879 ; Professor of Mathematics, Mt. 
Morris Academy, 1880-84 ; Professor of 
Mathematics, Carthage College, 1884-86 ; 
Superintendent of Schools, Carthage, 111., 
1886-89 ; Scholar in Mathematics, 
Clark University, 1889-90 ; Professor 
of Mathematics, State Normal School, 
Winona, Minn., 1890-91 ; Student in 
Mathematics, University of Halle, 1891- 
92 ; Professor of Mathematics, Fort Worth 
University, Texas, 1892-94 ; Student in 
Mathematics, University of Chicago, 1894- 
95 ; Principal of Academic Department of 
Coe College, 1895-96 ; Principal of High 
School, Lake City, Minn., 1896-97 ; Super- 
intendent of Schools, Lake City, Minn., 
1897-. 



486 



Titles of 



T. R. CHOSWELL: — 

A.B., Bowdoin College, 1891 ; Principal, 
Wilton Academy, 1891-94 ; Student in 
Pedagogy, Columbia College, 1894-95; 
Scholar in Pedagogy, Clark Univer- 
sity, 1895-97 ; Teacher in Public 
Schools of Chicago, 1897-98 ; Teacher 
in Stevens Point (Wis.) Normal School, 
1899. 

Author of : — 

Courses of Study in the Elementary 
Schools of the United States. Peda- 
gogical Seminary, April, 1897, Vol. 4, 
pp. 294-335. 

A Study of the Ungraded Schools of 
Maine. Maine School Beport, 1897, 
Appendix II., pp. 1-15. 

Amusements of Worcester School Chil- 
dren. Pedagogical Seminary, Sept., 
1899, Vol. 6, pp. 314-371. 

HENRY S. CURTIS: — 

A.B., Olivet College, 1894; A.B., Yale 
University, 1896 (Honors in Philosophy) ; 
Fellow in Psychology, Clark Uni- 
versity, 1895-97; Ph.D., Clark Uni- 
versity, 1898 ; Teacher, N. Y. Public 
Schools, 1898-. 

Author of ; — 

Learning without Books. Jour, of Peda- 
gogy, Jan., 1898, Vol. 11, pp. 86-90. 

Inhibition. Pedagogical Seminary, Oct., 
1898, Vol. 6, pp. 65-113. 

Child-study in Connection with the Vaca- 
tion Schools. (With G. E. Partridge.) 
Report on the Vacation Schools and 
Playgrounds, N. Y. City, Boroughs of 
Manhattan and the Bronx, 1898, pp. 
51-97. 

Child-study in Vacation Schools. Educa- 
tional Foundations, May, 1899. 

Child-study in the Playgrounds. Ibid., 
June, 1899. 

Plays and Playgrounds. (In press). 

ARTHUR HILL DANIELS: — 

B.A., Olivet College, 1887 ; Student, Yale 
Divinity School, 1887-90 ; B.D., Yale 
University, 1890 ; Student in Philosophy 
and Psychology, Yale University, 1890- 



92 ; Fellow in Psychology, Clark 
University, 1892-93 ; Ph.D., Clark 
University, 1893 ; Instructor in Phi- 
losophy, University of Illinois, 1893-95 ; 
Assistant Professor of Philosophy, ibid., 
1895-99; Professor of Philosophy, ibid., 
1899-. 

Author of : — 

The New Life : A Study of Regeneration. 

Am. Jour, of Psy., Oct., 1893, Vol. 6, 

pp. 61-106. 
The Memory After-image and Attention. 

Ibid., Jan., 1895, Vol. 6, pp. 558-564. 

SCHUYLER C. DAVISSON: — 

A.B., Indiana University, 1890; A.M., 
ibid., 1892; Instructor in Mathematics, 
ibid; 1890-93; Associate Professor in 
Mathematics, ibid., 1893-. Fellow in 
Mathematics, Clark University, 1895- 
96 ; Student, University of Tubingen, 
Germany, 1898-99. 

GEORGE E. DAWSON: — 

A.B., University of Michigan, 1887 ; Pro- 
fessor of Greek and English Literature, 
Carleton Institute, Earmington, Mo., 
1887-88 ; Student, University of Leipzig, 
1888-89; Principal, Oil City, Pa., High 
School, 1889-91 ; Professor of English and 
Literature, State Agricultural College, So. 
Dak., 1891-93 ; Instructor in English, 
University of Michigan, 1893-95 ; Fellow 
in Psychology, Clark University, 
1895-97, Ph.D., Clark University, 
1897 ; Professor of Psychology, Bible 
Normal College, Springfield, Mass., 1897-. 

Author of : — 

A Study in Youthful Degeneracy. Peda- 
gogical Seminary, Dec, 1896, Vol. 4, 
pp. 221-258. 

Series of Twelve Papers on Child-study. 
International Evangel, Sept., 1897- 
Sept., 1898. 

The Study of Man as Related to Religious 
Work. Biblical World, March, 1899. 

Interest, the Material of Instruction. 
Biblical World, June, 1899. 

Suggestions as to the Basis of a Sunday 
School Curriculum. Trans. III. Soc. 



Published Papers. 



487 



for Child-Study, Apr.-July, 1899, Vol. 
4, pp. 10-17. 
Psychic Rudiments and Morality. Am. 
Jour, of Psychology. (In press.) 

ALFRED T. DE LURY: — 

B.A., University of Toronto (with Honors 
and Medal in Mathematics), 1890 ; Fellow 
in Mathematics, Clark University, 
1890-91; Mathematical Master, Whet- 
ham College, Vancouver, 1891 ; Mathemat- 
ical Master, Collegiate Institute, Toronto, 
1892 ; Lecturer in Mathematics and Dean 
of the Residence, University of Toronto, 
1892- ; Member of the American Mathe- 
matical Society. 

Author of : — 

On Certain Deductions from the Theorem 
of Dr. Graves. Papers Math, and 
Phys. Soc, Toronto Univ., Tear 
1S90-91, pp. 22-30. 

Clark University. Tlie Varsity, Toronto, 
Jan. 27, 1891, Vol. 10, pp. 150-151. 

HENRY H. DONALDSON: — 

A.B., Yale University, 1879; Sheffield 
Scientific School, 1880 ; College of Physi- 
cians and Surgeons, N. Y. City, 1881 ; 
Fellow, Johns Hopkins University, 1881- 
83 ; Ph.D., Johns Hopkins University, 
1885; Associate in Psychology, ibid., 
1887-88 ; Assistant Professor of Neu- 
rology, Clark University, 1889-92; 
Professor of Neurology, University of 
Chicago, 1892-. 

Author of : — 

On the Detection and Determination of 
Arsenic in Organic Matter. (Under 
Prof. R. H. Chittenden.) Am. Chem. 
Jour., Oct., 1880, Vol. 2, pp. 235- 
244. 

The Influence of Digitaline on the Work 
of the Heart and on the Flow through 
the Blood Vessels. (With Dr. L. T. 
Stevens.) Jour, of Phys., Jan., 1883, 
Vol. 4, pp. 165-197. (See also note in 
Vol. 5, p. 45.) 

On the Temperature-Sense. Mind, July, 
1885, Vol. 10, pp. 399-416. 



Motor Sensations of the Skin. (With 
Dr. G. Stanley Hall.) Ibid., Oct., 
1885, Vol. 10, pp. 557-572. 

On the Relation of Neurology to Psy- 
chology. Am. Jour, of Psy., Feb., 
1888, Vol. 1, pp. 210-221. 

Anatomical Observations on the Brain 
and Several Sense-Organs of the Blind 
Deaf-Mute, Laura Dewey Bridgman. 
Part I. Ibid., Sept., 1890, Vol. 3, pp. 
293-842. Part II. Dec, 1891, Vol. 4, 
pp. 248-294. 

Cerebral Localization. Ibid., April, 1891, 
Vol. 4, pp. 113-130. 

Notes on Models of the Brain. Ibid., 
April, 1891, Vol. 4, pp. 130-131. 

The Size of Several Cranial Nerves in 
Man as Indicated by the Areas of 
their Cross-sections. (With T. L. 
Bolton.) Ibid., Dec, 1891, Vol. 4, 
pp. 224-229. 

The Extent of the Visual Area of the Cor- 
tex in Man as deduced from the Study 
of Laura Bridgman's Brain. Ibid., 
Aug., 1892, Vol. 4, pp. 503-513. 

Preliminary Observations on Some 
Changes caused in Nervous Tissues 
by Reagents, commonly used to 
harden them. Jour, of Morph., Jan., 
1894, Vol. 9, pp. 123-166. 

The Education of the Nervous System. 
Educational Review, Feb., 1895, Vol. 
9, pp. 105-121. 

The Growth of the Brain. (Contem- 
porary Science Series.) Walter Scott, 
London. Chas. Scribner's Sons, New 
York, 1895. 374 pp. 

Central Nervous System. Chapter X., 
Howell's Am. Text-Book of Physiol- 
ogy, W. B. Saunders, Philadelphia, 
1896, pp. 606-743. 

Observations on the Weight and Length 
of the Central Nervous System and 
of the Legs in Bull-frogs of Different 
Sizes. Jour, of Comp. Neurol., Dec, 
1898, Vol. 8, pp. 314-335. 

D. ELLIS DOUTY: — 

B.S., University of Washington, 1892; 
Assistant in Physics Laboratory, ibid., 
1895-96 ; Tutor in Physics, ibid., 1896- 



488 



Titles of 



98 ; Scholar in Physics, Clark Uni- 
versity, 1898-99. 

L. "WAYLAND DO"WLING : - 

Adrian College, 1889-90 ; Principal of 
Schools, Clayton, Mich., 1891-92 ; Pel- 
lovsr in Mathematics, Clark Univer- 
sity, 1892-95; Ph.D., Clark Univer- 
sity, 1895 ; Instructor in Mathematics, 
University of Wisconsin, 1895-98 ; Assist- 
ant Prof essor of Mathematics, ibid., 1898-; 
Member of the American Mathematical 
Society ; Member of the Wisconsin Acad- 
emy of Sciences, Arts, and Letters. 

Author of : — 

On the Forms of Plane Quintic Curves. 
Mathematical Review, April, 1897, Vol. 
1, pp. 97-119. 

FLETCHER B. DRESSLAR: — 

Instructor, Vincennes University, 1888 ; 
A.B., Indiana University, 1889 ; Princi- 
pal, High School, Princeton, Ind., 1889- 
90 ; Superintendent of Schools, Princeton, 
Ind., 1890-91 ; Scholar in Psychology, 
Clark University, 1891-92 ; Instruc- 
tor in Psychology, Indiana University, 
Sept. -Dec, 1892; FeUow In Psychol- 
ogy, Clark University, Jan., 1893-July, 
1894 ; Ph.D., Clark University, 1894 ; 
Professor of Psychology and Pedagogy, 
State Normal School, Los Angeles, Cal., 
1894-97 ; Assistant Professor of the Sci- 
ence and Art of Education, University of 
California, 1897-. 

Author of : — 

A Review of the Genus Simotilus. (With 
Ernest P. Bicknell.) Proe. Acad, of 
Nat. Sci., Philadelphia, 1884. 

A Review of the Family Scomhrinse 
(Illinois). (With Bert Fesler.) Bull, 
of U. 8. Fish Com., 1887. 

Temperance Legislation in Indiana. (Prize 
Essay, University of Indiana.) In- 
diana Student, March, 1887. 

Evils of Modern Immigration. (Prize 
Oration, University of Indiana. ) Ibid. , 
Dec, 1889. 

Fatigue. Pedagogical Seminary, June, 
1892, Vol. 2, pp. 102-106. 



A Sketch of Old Schoolhouses. Ibid., 
June, 1892, Vol. 2, pp. 115-125. 

Some Influences which affect the Rapid- 
ity of Voluntary Movement Am. 
Jour, of Psy., Aug., 1892, Vol. 4, pp. 
514-527. 

On Facial Vision and the Pressure Sense 
of the Drum of the Ear. Ibid., April, 
1893, Vol. 5, pp. 344-350. 

A New Illusion for Touch and an Ex- 
planation for the Illusion of Displace- 
ment of Certain Cross Lines in Vision. 
Ibid., Vol. 6, pp. 275-276. 

A New and Simple Method for Comparing 
the Perception of Rate of Movement in 
the Direct and Indirect Fields of Vision. 
Ibid., Vol. 6, p. 312. 

Psychology of Touch. Ibid., June, 1894, 
Vol. 6, pp. 50-54. 

Outline for a Study of Habit-Degenera- 
tion. Teachers'' Handbook for Child- 
Study. Published by Illinois Society 
for Child-Study, May, 1895, Vol. 1, 
pp. 21-23. 

Preparation for History in the Grades. 
Normal Exponent, 1895. 

The New Psychology and Its Pedagogical 
Significance. Proc. Cal. Teachers' 
Ass'n, Dec, 1895. 

Experiments in Psychology. Overland 
Monthly, Aug., Sept., Nov., Dec, 
1896 ; Feb., March, April, June, 1897. 

Education in Hawaii. Educational Re- 
view, Jan., 1898, Vol. 15, pp. 50-54. 

Genetic Psychology. Northxoestern 
Monthly, April, 1899, Vol. 9, pp. 
355-358. 

Guessing, as influenced by Number Pref- 
erences. Pop. Sci. Mo., April, 1899, 
Vol. 54, pp. 781-786. 

FRANK DREW : — 

Superintendent of Schools, Genoa, HI., 
1887-89; A.B., Indiana University, 
1890; A.M., ibid., 1891; Scholar in 
Psychology, Clark University, 1892- 
93; Fellow, 1893-95; Ph.D., Clark 
University, 1895 ; Instructor in Psy- 
chology, Indiana University, 1895-96; 
Teacher in State Normal School, Worces- 
ter, Mass., 1896-. 



Published Papers. 



Author of ; — 

Adenoids in Cliildren. Pedagogical Sem- 
inary, March, 1893, Vol. 2, pp. SOT- 
SOD. 

Love Poems of College Students. Ibid. 
Dec. 189-3, Vol. 2, pp. 504-505. 

Attention : Experimental and Critical. 
Am. Jour, of Fsy., July, 1896, Vol. 7, 
pp. 533-572. 

LINDSAY DUNCAN: — 

B.S., University of Maine, 1897 ; Scholar 
in Mathematics, Clark University, 
1897-99 ; Instructor in Mathematics and 
Engineering, Union College, Schenectady, 
N. Y., 1899-. 

ROBERT K. DUNCAN: — 

A.B., University of Toronto, 1892 ; Fel- 
low in Chemistry, Clark University, 
1892-93; Instructor in Physics and 
Chemistry, Auburn, N. Y., High School, 
1893-95 ; Instructor in Physics and Chem- 
istry, Dr. Julius Sach's Collegiate Insti- 
tute, New York, 1895-98; Non-Resident 
Student, Columbia University, 1897-98; 
Instructor in Physics and Chemistry, The 
Hill School, Pottstovra, Pa., 1898-. 

■WILLIAM FREDERICK DURAND: — 

Graduate, U. S. Naval Academy, 1880; 
Graduate, Course at Sea, 1882; Assistant 
Engineer, U. S. Navy, 1882-87 ; Graduate 
Student, Lafayette College, 1883-85 ; 
Ph.D., Lafayette College, 1888 ; Profes- 
sor of Mechanics, Michigan State Agri- 
cultural College, 1887-91 ; Scholar in 
Physics, Clark University, Nov. and 
Dec. , 1889 ; Professor of Marine Engi- 
neering, Cornell University, 1891-. 

Author of : — 

A Practical Method of Finding the Opti- 
cal Centre of an Objective and its Fo- 
cal Length. Am. 3Io. Micro. Jour. 
Aug., 1885, Vol. 6, p. 141. 

The Fundamental Conceptions of Me- 
chanics. Privately published, 1890. 

The Path of the Point of Contact of the 
Teeth of Gear Wheels. Sci. Am. Sup- 
plement, April 26, 1890, Vol. 29. 

An Interesting Experiment with the Mi- 



croscope. Am. Mo. Micro. Jour., 

June, 1890, Vol. 2, p. 136. 
The Behavior of Wood under Repeated 

and Varying Stress. Trans. Mich. 

Eng. Soc, 1891, p. 57. 
A New Form of Contour Caliper. Ibid. 

1891, p. 62. 

Decimal Subdivision by the Eye. Sibley 
Jour, of Eng., Jan., 1892, Vol. 6, p. 
138. 

Study of the Element of a Screw Propel- 
ler. Jour, of Am. Soc. of Naval En- 
gineers, 1892, Vol. 4, p. 73. 

Treatment of Non-Algebraic Curves for 
Maxima and Minima by Use of Ordi- 
dinates. Ibid. p. 71. 

The Influence of Shock on Propeller Effi- 
ciency. Ibid. p. 611. 

Some Points in the Philosophy of the 
Steamship. Gassier'' s Magazine, Nov., 

1892, Vol. 5, p. 35. 

Marine Engine Design. Marine Seview, 
1892, Vol. 6, Dec. 1, p. 6, and Dec. 8, 
p. 12. 

Relative Weight of Water and Fire Tube 
Boilers. American Shipbuilder, June 
20 and 27, 1893. 

Planning and Equipment of Modern Ship 
and Engine Building Plants. Bep. of 
Internat. Eng. Cong., Columbian Ex- 
position, Div. of Marine Eng. , Vol. 2, 
No. 28. 

The Limit of Propeller Efficiency as De- 
pendent on the Surface Form of the 
Propeller. Trans. Am. Soc. of Me- 
chanical Engineers, 1893, Vol. 14, p. 65. 

The Analysis of Certain Curves arising in 
Engineering Investigation. Jour, of 
Am. Soc. of Naval Engineers, 1893, 
Vol. 5, p. 543. 

On the Law of Frictional Resistance. 
Trans, of Am. Soc. of Naval Architects 
and Marine Engineers, 1893, Vol. 1, p. 
210. 

A Planimeter for Averaging Radial Ordl- 
nates. Sibley Jour, of Eng. 1893, 
Vol. 7, p. 64. 

Uses of Logarithmic Paper. Engineering 
News, Sept. 28, 1893. 

New Rules for Approximate Integration. 
Ibid., Jan. 18, 1894. 



490 



Titles of 



Mathematical Treatment of Continuous 
Functions by Approximate Methods. 
8iUey Jour, of Eng., Jan., 1894, Vol. 

8, p. 1.35. 

An Approximate Formula for the Wetted 
Surface of Ships. (With G. R. McDer- 
mott). Trans. Am. Soc. of Naval 
Architects and Marine Engineers, 1894, 
Vol. 2, p. 297. 

Water Tube BoUers for Marine Purposes. 
Sibley Jour, of Eng., Feb., 1895, Vol. 

9, p. 181. 

Electricity for Marine Propulsion. Gas- 
sier^ s Magazine, Jan., 1895, Vol. 8, 
p. 14.3. 

Curves showing the Relation between 
Equivalent Hollow and Solid Shafts. 
Jour, of Am. Soc. of Naval Engineers, 
1895, p. 507. 

The Number of Longitudinal Intervals in 
Ship Computations as Affecting the 
Accuracy of Integration for Displace- 
ment. Trans. Am. Soc. of Naval 
Architects and 3Iarine Engineers, 1895, 
Vol. 3, p. 129. 

Note on Different Forms of the Entropy 
Function. Physical Beview, Vol. 4, 
p. 343. 

Determination of the Current Curve Cor- 
responding to any Form of Alternating 
Electromotive Force in a Circuit with- 
out Iron. Sibley Jour, of Eng., 1897, 
p. 182. 

Method of Determining a Continuous 
Record of the Performance of a Marine 
Engine. Jour. Am. Soc. of Naval 
Engineers, 1897, p. 1. 

Graphical Determination of the Index of 
the Power according to which one 
quantity varies relative to another. 
Jour, of Franklin Inst., March, 
1897. 

An Experimental Study of the Influence 
of Surface on the Performance of Screw 
Propellers. Trans. Am. Soc. of Naval 
Architects and Marine Engineers, Vol. 
5, p. 107. 

Steamship Vibrations and the Balancing 
of Marine Engines. Marine Engineer- 
ing, June, July, August, 1897. 

Resistance and Propulsion of Ships. 



J. Wiley & Sons, New York, 1898. ix. 
-t-431 pp. 

The Approximate Treatment of Differen- 
tial Equations. Annals of Math., July, 
1898, p. 110. 

Entropy and Temperature Entropy Dia- 
grams. Jour. Soc. Naval Engineers, 
1898, p. 329. 

Electrical Propulsion for Torpedo Boats. 
Ibid., 1899, p. 53. 

FREDERICK EBY: — 

A.B., McMaster University, 1895; Gradu- 
ate Student, University of Chicago, 1895- 
97 ; Assistant Instructor, Morgan Paris 
Academy, Morgan Park, 111., 1897-98; 
Scholar in Pedagogy, Clark Univer- 
sity, 1898-99. 

Author of : — 

Suggestions for Work which can be done 
by Teachers. 43d Annual Beport 
State Supt. of Ed., Albany, N. Y., 
1897, Vol. 2, pp. 968-972. 

Study of the Use of Secret Languages 
(Syllabus). Ibid., pp. 972-973. 

Preliminary Study of Child-Esthetics 
(Syllabus). Ibid., p. 976. 

Educational Value of Manual Construc- 
tive Work. Education, April, 1898, 
Vol. 18, pp. 491-495. 

Translation of Pestalozzi's "Meine Nach- 
forschungen." (With Dr. Julia E. 
Bulkley.) (In press.) 

THOMAS "W. EDMONDSON: — 

B.A., London, Eng., 1888 (first in Honors 
and Senior Exhibitioner at Matriculation, 
June, 1886) ; Akroyd Scholar, 1888-90 ; 
Senior Mathematical Scholar, Pembroke 
College, Cambridge University, Eng., 
1888-91 ; B.A., Cambridge University 
(18th Wrangler in Mathematical Tripos), 
1891 ; Graduate Student in Chemistry, 
Physics, and Botany, ibid., 1891 ; Assist- 
ant Tutor in Mathematics and Physics, 
University Corr. College, Cambridge, Eng., 
1889-93 ; First Class in Intermediate 
Science Examination, London, 1893 ; 
Fellow in Physics, Clark University, 
1894-96; Ph.D., Clark University, 



Published Papers. 



491 



1896 ; Assistant Professor of Physics, 
New York University, 1896- ; Member of 
the American Mathematical Society, and 
American Physical Society. 

Author of : — 

Key to Briggs and Bryan's Coordinate 
Geometry. W. B. Clive & Co., 
London, New Yorli, and Sydney, 1891. 
192 pp. 

Worked Examples in Coordinate Geome- 
try. W. B. Clive & Co., London, New- 
York, and Sydney, 1891 ; 18 Exam. 
Papers + 62 pp. 

Mensuration and Spherical Geometry. 
(In. collaboration with W. Briggs, 
M.A., LL.B., etc.) W. B. Clive & 
Co., London, New York, and Sydney, 
1893. vi. + 112, ii. -|- 48 pp. 

Key to Briggs and Bryan's Elementary 
Text-book of Mechanics. (In collab- 
oration with Bion Reynolds, M.A.) 
W. B. Clive & Co. , London, New York, 
and Sydney, 1895. viii. -1- 172 pp. 

On the Disruptive Discharge in Air and 
Liquid Dielectrics. Physical Beview, 
Feb., 1898, Vol. 6, pp. 65-97. 

CHARLES L. EDWARDS: — 

B.S., Lombard University, 1884; B.S., 
Indiana University, 1886 ; A.M., ibid., 
1887 ; Student, Johns Hopkins University, 
1887-89; Ph.D., University of Leipzig, 
1890 ; Fellow in Morphology, Clark 
University, 1890-91 ; Honorary Fel- 
low, Clark University, 1891-92; 
Assistant Professor of Biology, University 
of Texas, 1892-93 ; Adjunct Professor of 
Biology, ibid. , 1893-94 ; Professor of 
Biology, University of Cincinnati, 1894- ; 
Member of the American Society of Natu- 
ralists ; Morphological Society ; President 
of the American Folk-Lore Society, 1899 ; 
Socio Corresponsal, La Sociedad de Geo- 
grafia y Estadistica, Mexico ; Socio 
Honorario, La Sociedad Mexicana de 
Historia Natural ; Socio Honorario, La 
Sociedad Antonio Alzate. 

Author of : — 

The Relation of the Pectoral Muscles in 
Birds to the Power of Flight. Ameri- 



can Naturalist, Jan., 1886, Vol. 20, 
pp. 2.5-29. 

A Review of the American Species of the 
Tetraodontidae. (With President David 
S. Jordan.) Proc. of U. S. Nat. Mus., 
1886, p. 232. 

The Influence of Warmth upon the Irrita- 
bility of Frog's Muscle and Nerve. 
Studies from Biol. Lab., Johns Hop- 
kins University, July, 1887. 

Winter Roosting Colonies of Crows. Am. 
Jour, of Psy., May, 1888, Vol. 1, pp. 
436-459. 

Notes on the Embryology of Miilleria 
Agassizii Sel. , a Holothurian common 
at Green Turtle Bay, Bahamas. Johns 
Hopkins University Circular, 1889, 
Vol. 8, p. 37. 

Folk-Lore of the Bahama Negroes. Am. 
Jour, of Psy., Aug., 1889, Vol. 2, pp. 
519-542. 

Beschreibung einiger neuen Copepoden 
und eines neuen oopepodenahnlichen 
Krebses, Leuckertella paradoxa. 
Archiv f. Naturgeschichte, Berlin, 
1891, Jahrg. 57, Bd. 1, 36 pp. 

Some Tales from Bahama Folk-Lore. 
Jour, of Am. Folk-Lore, 1891, Vol. 4, 
pp. 47-54. 

Some Tales from Bahama Folk-Lore. 
Fairy Tales. Ibid., pp. 247-252. 

Bahama Songs and Stories. (Vol. 3 of 
Memoirsofthe Am. Folk-Lore Society.) 
Houghton, Mifflin & Co., Boston, 1895. 
Ill pp. 

Notes on the Biology of Phrynosoma Cor- 
nutum Harlan. Zool. Aneeiger, 1896. 

STAFFORD C. EDWARDS: — 

Classical Graduate, Oneonta, N. Y., 
Normal, 1891 ; A.B., Brown University, 
1895 ; A.M., Philosophy and Pedagogy, 
ibid., 1896 ; Student Teacher of History and 
English, High School, Providence, R. I., 
1895-96; Principal of Greenport, N. Y., 
Union School, 1896-97 ; Scholar in 
Pedagogy, Clark University, Oct., 
1897-March, 1898 ; Teacher of Mathe- 
matics, Jamaica, N. Y., Normal School, 
March-June, 1898 ; Principal Union School, 
Schuylerville, N. Y., 1898-. 



492 



Titles of 



ALEXANDER CAS^WELL ELLIS: — 

Head Master, Classical High School, 
Chapel Hill, N. C, 1891-92; A.B., 
University of North Carolina, 1894 ; 
Scholar in Pedagogy, Clark Univer- 
sity, 1894-95 ; Fellow in Psychology, 
1895-97 ; Ph.D. , Clark University, 
1897 ; Adjunct Professor of Pedagogy, 
University of Texas, 1897- ; Member of 
American Association for the Advance- 
ment of Physical Education ; Member 
of Illinois ChOd-Study Society ; Fellow, 
Texas Academy of Science. 

Author of : — 

Sunday School Work and Bible Study in 
the Light of Modern Pedagogy. ' Peda- 
gogical Seminary, June, 1896, Vol. 3, 
pp. 363-412. 

A Study of Dolls. ("With G. Stanley Hall. ) 
Ibid., Dec, 1896, Vol. 4, pp. 129-175. 

Suggestions for a Philosophy of Education. 
Ibid., Oct., 1897, Vol. .5, pp. 159-201. 

Play in Education. Northwestern Monthly, 
Nov., 1898 ; and Bep. of Ad. and Proc. 
Texas State Teachers' Ass''n, 1898. 

Reading and Literature in the Schools. 
Bep. of Ad. and Proc. Texas State 
Teachers'' Ass''n, 1898. 

The Science of Education in the Univer- 
sity of Texas, and Some of Its Prob- 
lems. University Becord, University 
of Texas, Vol. 1, No. 2. 

BENJAMIN P. ELLIS: — 

A.B., Dartmouth College, 1889 ; Instruc- 
tor in Physics and Mathematics, High 
School, Peoria, HI., 1889-92; Scholar in 
Physics, Clark University, 1892-93 ; 
Instructor, High School, Peoria, 111., 
1893-. 

PERCY NORTON EVANS: — 

B.A.Sc, McGill University, Montreal, 
1890 ; Assistant in Chemistry, ibid., 1890- 
91 ; Student, University of Leipzig (McGill 
Exhibition of 1851 Science Scholar), 1891- 
93 ; Ph.D., University of Leipzig, 1893 ; 
Honorary Fellow in Chemistry, Clark 
University, 1894 ; Assistant in Chemis- 
try to Professor Atwater, Wesleyan Uni- 



versity, 1894-95 ; Instructor in Chemistry, 
Purdue University, 1895-96 ; Associate 
Professor of Chemistry, ibid., 1896- ; 
Member of the Indiana Academy of 
Science. 

Author of : — 

Condensation von j3-Diketonen mit Harn- 
stoff und Thioharnstoff. Jour, fur 
praktische Chemie, Vol. 46, p. 352. 

Condensationsprodukte der /3-Diketone 
mit Harnstoff, Guanidin, und Thioharn- 
stoff. Ibid., Vol. 48, pp. 489-517. 

Food Adulteration. Purdue University 
Monographs, 1896. 17 pp. 

An Introductory Course in Quantitative 
Analysis. Ginn & Co., Boston, 1897. 
iv. -1-83 pp. 

Note on Some Combustion Products of 
Natural Gas. Pi-oc. Ind. Acad, of 
Science, 1897, pp. 133-134. 

Note on the Iodine Number of Linseed 
Oil. Ibid., 1898, pp. 160-163. 

H. L. EVERETT: — 

A.B., Brown University, 1886; A.M., 
Harvard University, 1889 ; Student, Berlin 
University, 1889-90; Professor, Utah 
Agricultural College, 1890-92 ; Scholar 
in Psychology, Clark University, 
1896-97 ; Honorary FeUow in Psy- 
chology, 1897-98 ; Instructor, Macken- 
zie College, S. Paulo, Brazil, 1898-. 

ALBERT C. EYCLESHYMER: — 

Assistant in Animal Morphology, Uni- 
versity of Michigan, 1888-89 ; Assistant 
in Botany, ibid., 1889-90 ; Chief Assist- 
ant, AUis Lake Laboratory, 1890-91 ; 
B.S., University of Michigan, 1891 ; 
Fellow in Morphology, Clark Uni- 
versity, 1891-92 ; Fellow in Biology, 
University of Chicago, 1892-93 ; Assistant 
in Anatomy and Histology, ibid., 189.S- 
95; Ph.D., University of Chicago, 1895 ; 
Tutor in Anatomy and Histology, ibid., 
1895-. 
Author of : — 

Celloidin Imbedding in Plant Histology. 

Botanical Gazette, Vol. 15, pp. 272- 

295. 



Published Papers. 



493 



Notes on Celloidin Technique. American 
Naturalist, Vol. 26, pp. 354-358. 

Club-root (Plasmodiophora brassioae 
Wor.) in the United States. Journal 
of Mycology, Vol. 7, pp. 79-90. 

Paraphysis and Epiphysis in Amblystoma. 
Anatomisclier Anzeiger, April 7, 1892, 
Vol. 7, pp. 215-217. 

The Cleavage of the Amphibian Ovum. 
(With E. O. Jordan.) Ibid. Sept. 15, 

1892, Vol. 7, pp. 622-624. 

The Development of the Optic Vesicles in 
Amphibia. Jour, of Morph., April, 

1893, Vol. 8, pp. 189-194 ; Figs. 1-6. 
On the Cleavage of Amphibian Ova. 

(With E. O. Jordan.) Ibid., Sept., 

1894, Vol. 9, pp. 407-416 ; PI. xxvi. 
The Early Development of Amblystoma 

with Observations on some other 
Vertebrates. Ibid., Feb., 1895, Vol. 
10, pp. 343-418 ; Pis. xviii-xxii. 

FREDERICK C. FERRY : — 

A.B., Williams College, 1891; Instructor 
in Latin and Mathematics, ibid., 1891- 
94; A.M., ibid., 1894 ; Graduate Student 
in Mathematics, Harvard University, 
1894-95; A.M., ibid., 1895; Fellow in 
Mathematics, Clark University, 1895- 
98; Ph.D., Clark University, 1898; 
Assistant Professor of Mathematics, Wil- 
liams College, 1899-. 

Author of : — 

Geometry on the Cubic Scroll of the First 
Kind. Archiv for Mathematik og Na- 
turvidenskab, B. xxi, Nr. 2. 

DANIEL POLKMAR: — 

A.B., Western College, 1884 ; A.M., ibid., 
1888 ; Student, Harvard Divinity School, 
1888-89 ; Fellow in Psychology, Clark 
University, 1889-90 ; Professor of Po- 
litical Science and Psychology, Indiana 
Normal University, 1890-91 ; President 
and Professor of Social Science, ibid., 
1891-92 ; Professor of Social Science, 
Western Michigan College, 1892-93 ; Presi- 
dent, ibid., 1893 ; Lecturer in Sociology, 
University of Chicago, 1893-95 ; Professor 
of Psychology and Pedagogy, State Nor- 



mal School, Milwaukee, Wis., 1895-98 ; 
Student, University of Paris, 1898-99; 
Professor of Anthropology, University 
Nouvelle, Brussels, Belgium, 1898 ; Doc- 
teur 6s sciences sooiales, ibid., June, 1899 ; 
Fellow of the Royal Statistical Society, 
London ; Member of : Anthropologische 
Gesellschaft in Wien, Anthropological So- 
ciety of Washington, American Associa- 
tion for the Advancement of Science, 
American Academy of Political and Social 
Science, American Statistical Association, 
American Institute of Sociology, Wisconsin 
Academy of Sciences, Arts, and Letters. 

Author of : — 

Instruction in Sociology in Institutions of 
Learning. Eeprint from Proc. of Nat. 
Conf. of Charities and Correction, 
Boston, 1894. 19 pp. Also reprinted 
as Chapter XXVII of the Beport of 
U. S. Com. of Ed. for 1894-95, Vol. 2, 
pp. 1211-1221. 

A Sociological Ideal View of Normal 
Schools. Proc. of Inter. Cong, of Ed. 
of the World's Columbian Exposition, 
1893, pp. 422-428. Published by Am. 
Ed. Ass'n, New York, 1893. 

New Views in Social Science, etc. The 
Interrogator, Feb.-June, 1893. 

The Ideal in Professional Training. Edu- 
cation, April, 1896. 

The Duration of School Attendance in 
Chicago and Milwaukee. Proc. Wis- 
consin Academy of Sciences, Arts, and 
Letters, 1897, Vol. 12, pp. 255-305. 

Anthropology, not Sociology, as an ade- 
quate Philosophy of Human Life. 
Proc. A. A. A. S., 1898. 

Sociology as based upon Anthropology. 
Am. Jour, of Soc. Sci., 1898. 

Anthropologic Philosophique. (In press.) 

CLEMENS JAMES FRANCE: — 

A.B., Hamilton College, 1898; Scholar 
in Psychology, Clark University, 
1898-99. 

Author of: — 

The Psychology of Ownership. (With 
L. W. Kline.) Pedagogical Seminary. 
(In press.) 



494 



Titles of 



JOSEPH IRWIN FRANCE: — 

A.B., Hamilton College (Root Scientific 
Fellowship, with Honors in Biology), 
1895 ; Student, University of Leipzig, 
1895-96 ; Scholar in Psychology, Clark 
University, 1896-97 ; A.M. (honorary), 
Hamilton College, 1898 ; Supervisor and 
Instructor in Science, Jacob Tome Insti- 
tute, Port Deposit, Md., 1897- ; Student, 
College of Physicians and Surgeons, Balti- 
more, Md., 1898-99. 

Author of : — 

The Conservation of Cosmos. An Essay. 

Gressner & Schramm, Leipzig, 1896. 

18 pp. 
Nature-Study. Educational Seview, 

March, 1899, Vol. 17, pp. 292-295. 

ALEXANDER FRASER: — 

A.B., Dalhousie College, 1889; Graduate 
Student, Harvard University, 1889-90 ; 
FelloT!!r in Psychology, Clark Uni- 
versity, 1891-92 ; Student in Medicine, 
Dalhousie University, 1893-97 ; M.D., 
CM., ibid., 1897 ; Lecturer in Psychology, 
Halifax Ladies' College, 1893-94; In- 
structor in Psychology, Halifax School for 
the Blind, 1894-95 ; House Surgeon, Vic- 
toria General Hospital, Halifax, N. S., 
1897-98 ; Practising Physician and Sur- 
geon, New Glasgow, N. S., 1898-. 

Author of : — 

Visualization as a Chief Source of the Psy- 
chology of Hobbes, Locke, Berkeley, 
and Hume. Am. Jour, of Psy., Dec, 
1891, Vol. 4, pp. 230-247. 

The Psychological Foundation of Natural 
Kealism. Ibid., April, 1892, Vol. 4, 
pp. 429-450. 

The Psychological Basis of Hegelism. 
Ibid., July, 1893, VoL 5, pp. 472-495. 

JOHN S. FRENCH: — 

A.B., Bowdoin College, 1895; Scholar 
in Mathematics, Clark University, 
1895-96 ; Fellow, 1896-98 ; Ph.D. , 
Clark University, 1898 ; Supervisor and 
Instructor in Mathematics, Jacob Tome 
Institute, 1898-. 



Author of : — 

On the Theory of the Pertingents to a 
Plane Curve. (In press.) 

JOHN PHELPS FRUIT : — 

A.B., Bethel College, Ky.,1878; Instruc- 
tor of Latin and Mathematics, High 
School, Parker's Grove, Ky., 1878-79; 
Professor of Latin and Greek, Bardstown 
Institute, Ky., 1879-81 ; A.M., Bethel 
College, 1881 ; President, Liberty Female 
College, Glasgow, Ky., 1881-83; Professor 
of English Literature, Bethel College, 
1883-97 ; Scholar in Psychology, Clark 
University, 1891 ; Graduate Student, 
University of Leipzig, 1894-95 ; Ph.D., 
University of Leipzig, 1895 ; Professor of 
English Language and Literature, William 
JeweUCoUege, 1897-; Memberof : Modern 
Language Association, American Dialect 
Society, American Statistical Association, 
Southern History Association. 

Author of : — 

The Evolution of Figures of Speech. 
Modern Language Notes, Dec, 1888. 

Browning and Tennyson. Ibid., May, 
1890. 

A Plea for the Study of Literature from 
the Esthetic Standpoint. Pub. of the 
Modern Language Ass'n, 1891, Vol. 6, 
No. 1. 

Shakespeare's Egoism. Poet Lore, Sept., 
1899, Vol. 1, pp. 406-407. 

The Destiny of Marriage : Portia and the 
Caskets. Ibid., Feb., 1891, Vol. 3, 
pp. 69-74. 

Uncle Remus in Phonetic Spelling. Dia- 
lect Notes, Boston, 1892, Part 4, pp. 
196-198. 

The Ideal the Need of the People. South- 
ern Magazine, May, 1894. 

John Milton. Seminary Magazine (Louis- 
ville, Ky.), March, 1899. 

The Mind and Art of Poe's Poetry. A. S. 
Barnes & Co., New York, 1899. 144 pp. 

HOMER GAGE:— 

A.B., Harvard University, 1882; A.M., 
ibid., 1887; M.D., ibid., 1887; Physician 
and Surgeon, Worcester, Mass., 1888- ; 



Published Papers. 



495 



Honorary Scholar in Anatomy, Clark 
University, 1889-90 ; Surgeon to Me- 
morial, St. Vincent, and Worcester City- 
Hospitals ; Consulting Surgeon to Baldwin- 
ville Cottage Hospital. 

BENJAMIN IVES OILMAN: — 

A.B., "Williams College, 1872; A.M., 
ibid., 1880; Fellow, Johns Hopkins Uni- 
versity, 1881-83 ; Lecturer at Princeton, 
Harvard, and Columbia, 1890-91 ; In- 
structor in Psychology, Clark Uni- 
versity, 1892-93 ; Curator, Museum of 
Fine Arts, Boston, Mass., 1893-. 

Author of: — 

On Propositions and the Syllogism. On 
Propositions called Spurious. J. H. 
U. Circular, Aug., 1882, pp. 240-241. 

On Operations in Relative Number. Johns 
Hopkins Studies in Logic, 1882. 

A Study of the Inductive Theories of 
Bacon, Whewell, and Mill. Colorado 
College Studies, 1890, pp. 17-26. 

Zuni Melodies. Jour, of Am. Arch, and 
Eth., Vol. 1, 1891, pp. 65-91. 

On some Psychological Aspects of the 
Chinese Musical System. Philosophi- 
cal Review, Jan. and March, 1892, Vol. 
1, pp. 54-71, 154-178. 

On the Properties of a One-dimensional 
Manifold. Mind, Oct., 1892, N. S., 
Vol. 1, pp. 518-526. 

Report on an Experimental Test of Musi- 
cal Expressiveness. Am. Jour, of Psy., 
Vols. 4 and 5, Aug. and Oct., 1892. 

Syllabus of Lectures on the Psychology of 
Pain and Pleasure. Ibid., Oct., 1893, 
Vol. 6, pp. 3-60. 

HENRY H. GODDAHD: — 

A.B., Haverford College, 1887; A.M., 
ibid., 1889 ; Instructor in Latin and His- 
tory, University of Southern California, 
1887-88 ; Graduate Student, Haverford 
College, 1888-89 ; Principal, Damascus 
Academy, Ohio, 1889-91 ; Instructor in 
Latin and Greek, Oak Grove Seminary, 
Vassalboro, Me., 1891-93 ; Principal, ibid., 
1893-96 ; Scholar in Psychology, Clark 
University, 1896-97 ; Fellow, 1897- 



99; Ph.D., Clark University, 1899; 

Professor of Psychology and Pedagogy, 
State Normal School, West Chester, Pa., 
1899-. 

Author of : — 

The Effects of Mind on Body as evidenced 
by Faith Cures. Am. Jour, of Psy., 
April, 1899, Vol. 10, pp. 431-502. 

JOHN H. GRAY, JR.: — 

B.S., Univer.sity of California, 1887; As- 
sistant to State Analyst, California, 1887- 
90 ; Assistant in Chemistry, University 
of California, 1889-90 ; Instructor in 
Chemistry, ibid, 1890-92 ; Fellow in 
Chemistry, Clark University, 1892- 

94 ; Instructor in Physics and Chemistry, 
State Normal School, Chico, Cal., 1894- 

95 ; Assistant in Chemistry, University of 
California, 1895-96 ; Instructor in Chem- 
istry, ibid., 1896-. 

CEPHAS GUILLBT: — 

A.B., Victoria University, Cobourg, 
Ont. (Honors in English, French and 
German Literature), 1887 ; Modern Lan- 
guage Master, Perth, Ont., 1887-90 ; 
Modern Language Master, Ottawa, Ont., 
1890-94 ; Student at Law, Osgoode Hall, 
Toronto, 1894-95 ; Scholar in Psy- 
chology, Clark University, 1895-96 ; 
FeUow, 1896-98. 

H. R. GURLEY: — 

United States Naval Academy, 1877-79 ; 
Assistant Resident Physician, Children's 
Hospital, Washington, D. C, 1882-84 ; 
M.D. (First Honor), National Medical 
College, Washington, D. C, 1884 ; Resi- 
dent Physician, United States Soldiers' 
Home Hospital, Washington, D. C, 1884- 
85 ; Scientific Assistant, United States 
National Museum, Washington, D. C, 
1886-90 ; Scientific Assistant, Biological 
Laboratory, United States Fish Com- 
mission, Washington, D. C, 1890-95 ; M. 
Sc, Columbian University, 1895 ; Fellow 
in Biology, Clark University, 1895- 

96 ; Junior Assistant Physician, Worcester 
Insane Hospital, 1896-97 ; Assistant Phy- 
sician, ibid., 1897-. 



496 



Titles of 



Author of : — 

The Geologic Age of the Graptolite 
Shales of Arkansas. Ann. Mep. Geol. 
Survey, Arkansas, 1890, Vol. 3, pp. 
401-418, PI. 9. 

Some Recent Graptolite Literature. 
American Geologist, 1891, pp. 35-43. 

The Classification of the Myxosporidia, 
a Group of Protozoan Parasites infest- 
ing Fishes. Bull. U. S. Fish Com., 

1891, pp. 407-420. 

The Myxosporidia, or Psorosperms of 
Fishes, and the Epidemics produced 
by them. Bep. U- S. Fish. Com., 

1892, pp. 65-304, PI. 1-47. 

The North American Graptolites. Journal 
of Geology, 1896, Vol. 4, pp. 63-102 ; 
291-311. PI. 4-5. 

G. STANLEY HALL : — 

A.B., Williams College, 1867; A.M., 
1870 ; Union Theological Seminary, N. Y., 
1867-68 ; Universities Berlin and Bonn, 
1869-70 ; Union Theological Seminary, 
N. Y., 1870-71; Universities of Berlin 
and Heidelberg, 1871-72 ; Professor of 
Philosophy, Antioch College, 1872-76; 
Instructor, Harvard University, 1876-78 ; 
Ph.D., Harvard University, 1878; Uni- 
versities of Berlin and Leipzig, 1878-80 ; 
Lecturer in Harvard University and 
Williams College, 1880-81 ; Professor of 
Psychology, Johns Hopkins University, 
1881-88 ; LL.D., University of Michigan, 
1888, and Williams College, 1889 ; Presi- 
dent, and Professor of Psychology, 
Clark University, 1888- ; Editor and 
Founder of American Journal of Psychol- 
ogy (Founded in 1887), and Pedagogical 
Seminary (Founded in 1891) ; Resident 
Fellow of the American Academy of Arts 
and Sciences ; Resident Member of the 
Massachusetts Historical Society ; Mem- 
ber of American Antiquarian Society. 

Author of : — 

John Stuart Mill. Williams Quarterly, 
Williamstown, Mass., Aug., 1867. 

Digest of Dorner's Theology. Presby- 
terian Review, Jan., 1873, pp. 60-93. 

Hegel as the National Philosopher of Ger- 



many. (Translated from the German 
of Dr. Carl Rosenkranz. ) Gray, Baker, 
& Co., St. Louis, 1874. 159 pp. 

Hegel : His FoUovcers and Critics. Jour, 
of Spec. Philos., 1878, Vol. 12, pp. 93- 
103. 

Color Perception. Proc. Am. Acad, of 
Arts and Sciences, March, 1878, Vol. 
3, pp. 402-413. 

The Muscular Perception of Space. Mind, 
Oct., 1878, Vol. 3, pp. 433-450. 

The Philosophy of the Future. Nation, 
Nov. 7, 1878, Vol. 27, pp. 283-284. 

Philosophy in the United States. Mind, 
Jan., 1879, Vol. 4, pp. 89-105; also 

. Pop. Sci. Mo. , Suppl. No. 1, 1879, p. 57. 

Ueber die Abhangigkeit der Reactions- 
zeiten vom Ort des Reizes. (With 
J. V. Kries.) Archiv f. Physiol. (Du 
Bois-Reymond), Suppl. Band, 1879, 
pp. 1-10. 

Die willkiirliche Muskelaction. (With 
Hugo Kronecker.) Ibid., pp. 11-47. 

Laura Bridgman. Mind, April, 1879, 
Vol. 4, pp. 149-172. 

Recent Researches in Hypnotism. Ibid., 
Jan., 1881, Vol. 6, pp. 98-104. 

Aspects of German Culture. James R. 
Osgood & Co., Boston, 1881. 320 pp. 

Moral and Religious Training of Children. 
Princeton Review, Jan., 1882, Vol. 10, 
pp. 26-48. 

Chairs of Pedagogy in our Higher Institu- 
tions of Learning. N. E. A., March, 
1882 ; U. S. Bur. of Ed., Circular of 
Information, No. 2, 1882, pp. 35-44. 

Optical Illusions of Motion. (With Dr. 
H. P. Bowditch.) Jour, of Phys., Aug., 

1882, Vol. 3, pp. 297-307. 

The Education of the Will. Princeton 
Review, Nov., 1882, Vol. 10, pp. 306- 
325. Reprinted in Pedagogical Semi- 
nary, June, 1892, Vol. 2, pp. 72-89. 

Methods of Teaching History. (Edited.) 
Ginn, Heath & Co., Boston, 1883. 
xii. + 296 pp. 

Educational Needs. If. A. Rev., March, 

1883, Vol. 136, pp. 284-290. 
Reaction-Time and Attention in the Hyp- 
notic State. Mind, April, 1883, Vol. 8, 
pp. 170-182. 



Published Papers. 



497 



Contents of Children's Minds on entering 
School. Princeton Beview, May, 1883, 
Vol. 11, pp. '2i9-272 ■ Pedagogical 
Seminary, June, 1891, Vol. 1, pp. 139- 
173. Issued in pamphlet form by 
E. L. Kellogg & Co., New York, 1893. 
66 pp. 

Education and Theology. Nation, July 
26, 1883, Vol. 37, pp. 81-82. 

The Study of Children. (Privately printed.) 
N. Somerville, Mass., 1883, 13 pp. 

Report of the Visiting Committee of the 
Alumni of Williams College, Williams- 
town, Mass., 1884. 11 pp. 

Bilateral Asymmetry of Function. (With 
E. M. Hartwell.) Mind, Jan., 1884, 
Vol. 9, pp. 93-109. 

New Departures in Education. N. Am. 
Rev., Feb. 1885, Vol. 140, pp. 144- 
152. 

The New Psychology. Andover Beview, 
Feb. and March, 1885, Vol. 3, pp. 120- 
135, 239-248. Opening lecture, Johns 
Hopkins University, Oct. , 1884. 

Experimental Psychology. Mind, April, 
1885, Vol. 10, pp. 245-249. 

Children's Collections. Nation, Sept. 3, 
1885, Vol. 41, p. 190; reprinted In 
Pedagogical Seminary, June, 1891, 
Vol. 1, pp. 234-237. 

Overpressure in Schools. Nation, Oct. 
22, 1885, Vol. 41, pp. 338-339. 

Motor Sensations of the Skin. (With 
Dr. H. H. Donaldson.) Mind, Oct., 
1885, Vol. 10, pp. 557-572. 

Studies of Rhythm. (With Joseph Jas- 
trow.) Ibid., Jan., 1886, Vol. 11, pp. 
55-62. 

Hints toward a Select and Descriptive 
Bibliography of Education. (With 
John M. Mansfield.) D. C. Heath & 
Co., Boston, 1886. 309 pp. 

Psychical Research. Am. Jour, of Psy., 
Nov., 1887, Vol. 1, pp. 128-146. 

Psychology. (Reviews.) Am. Jour, of 
Psy., Nov., 1887, Vol. 1, pp. 146-164. 

Dermal Sensitiveness to Gradual Pressure- 
Changes. (With Y. Motora.) Ibid., 
Nov., 1887, Vol. 1, pp. 72-98. 

The Story of a Sand Pile. Scribner''s 
Magazine, June, 1888, Vol. 3, pp. 
2k 



690-696. Reprint, E. L. Kellogg & Co., 
N. Y., 1897. 20 pp. 

Introduction to American Edition of 
Preyer's Senses and Will. (Translated 
by H. W. Brown.) New York, 1888. 

Address Delivered at the Opening of Clark 
University, Opening Exercises, pp. 9- 
32, Worcester, Mass., Oct. 2, 1889. 
(Published by the University.) 

A Sketch of the History of Reflex Action. 
Am. Jour, of Psy., Jan., 1890, Vol. 3, 
pp. 71-86. 

How to teach Reading, and What to Read 
in School. D. C. Heath & Co., Boston, 
1890. 40 pp. (First edition, 1886.) 

Children's Lies. Am. Jour, of Psy., Jan., 
1890, Vol. 3, pp. 59-70. Reprinted in 
Pedagogical Seminary, June, 1891, 
Vol. 1, pp. 211-218. 

The Training of Teachers. Forum, Sep- 
tember, 1890, Vol. 10, pp. 11-22. 

First Annual Report to the Board of 
Trustees of Clark University, Worces- 
ter, Mass., Oct. 4, 1890. 53 pp. 

University Study of Philosophy. Discus- 
sion. Begents' Bep. Univ., State of 
New York, 1891, Vol. 105, pp. 335-338. 

Boy Life in a Massachusetts Country Town 
Thirty Years Ago. Proe. Am. Antiq. 
Soc, Worcester, Mass., 1891, N. S., 
Vol. 7, pp. 107-128. 

Educational Reforms. Pedagogical Semi- 
nary, Jan., 1891, Vol. 1, pp. 1-12. 
Appeared also as Rif orme Pedagogiche 
in n Bisveglio Educativo, Aprile 13- 
16, 1892, Anno 8, pp. 207-208, 210-211. 

The Principles of Psychology. By William 
James. (Review.) Am. Jour, of Psy., 
Feb., 1891, Vol. 3, pp. 578-591. 

Contemporary Psychologists. I. Edward 
Zeller. Ibid., April, 1891, Vol. 4, pp. 
156-175. 

Enseignement des Sciences. Bevue Sci- 
entifique, April 4, 1891, Vol. 47, pp. 
430-433. 

Notes on the Study of Infants. Peda- 
gogical Seminary, June, 1891, Vol. 1, 
pp. 127-138. 

The Moral and Religious Training of 
Children and Adolescents. Ibid., pp. 
196-210. 



498 



Titles of 



Second Annual Report to the Board of 
Trustees of Clark University, Worces- 
ter, Mass., Sept. 29, 1891. 66 pp. 

The New Movement in Education. An 
address delivered before the School of 
Pedagogy of the University of the City 
of New York, Dec. 29, 1891. Pub- 
lished by the Women's Advisory Com- 
mittee, New York, 1891. 20 pp. 

The Outlook in Higher Education. Acad- 
emy, Boston, Mass., Jan., 1892, Vol. 
6, pp. 543-562. 

Health of School ChOdren as affected 
by School Buildings. Report of Froc. 
Dept. of Superintendence, held in 
Brooklyn, N. Y., Feb., 1892, pp. 163- 
172. Also Proc. N. E. A., 1892, pp. 
682-691. 

Moral Education and WOl Training. 
Pedagogical Seminary, June, 1892, 
Vol. 2, pp. 72-89. 

Child-study as a Basis for Psychology and 
Psychological Teaching. Beport of 
Com. of Ed., 1892-93, Washington, D.C., 
1895, Vol. 1, pp. 357-358, 366-370. 

Third Annual Report to the Board of 
Trustees of Clark University, Worces- 
ter, Mass., April, 1893. 168 pp. 

Psychological Progress. The Liberal Club, 
Buffalo, N. Y., Nov. 16, 1893. 

Child-study : The Basis of Exact Educa- 
tion. Forum, Dec, 1893, Vol. 16, 
pp. 429-441. 

American Universities and the Training 
of Teachers. lUd., April, 1894, Vol. 
17, pp. 148-159. 

Universities and the Training of Pro- 
fessors. Ibid., May, 1894, Vol. 17, 
pp. 297-309. 

Scholarships, Fellowships, and the Train- 
ing of Professors. Ibid., June, 1894, 
Vol. 17, pp. 443-454. 

Research the Vital Spirit of Teaching. 
Ibid., July, 1894, Vol. 17, pp. 558-570. 

Child-study in Summer Schools. Regents^ 
Bulletin, University of the State of 
New York, No. 28, July, 1894. Albany, 
N. Y., 1895, Vol. 1, pp. 333-336. 

The New Psychology as a Basis of Edu- 
cation. Forum, August, 1894, Vol. 17, 
pp. 710-720. 



Address at the Bryant Centennial, Aug. 
16, 1894. Bryant Memorial, Cum- 
mington, Mass., 1894, pp. 67-69. 

Address. Dedication of the Hasten Free 
Public Library Building, North Brook- 
field, Mass., September 20, 1894. pp. 
11-21. 

On the History of American College Text- 
Books and Teaching in Logic, Ethics, 
Psychology, and Allied Subjects. 
Proc. Am. Antiq. Soc, Worcester, 
Mass., 1894, N. S., Vol. 9, pp. 137-174. 

Remarks on Rhythm in Education. Proc. 
N. E. A., 1894, pp. 84-85. 

Child-study. Ibid., 1894, pp. 173-179. 

Practical Child-study. Jour, of Ed., Dec. 
13, 1894, Vol. 40, pp. 391-392. 

Topical Syllabi for 1894-1895. These 
were one- or two-page leaflets, pre- 
pared by Dr. Hall, and privately printed 
at Worcester, Mass. They covered : 
I. Anger ; II. Dolls ; III. Crying and 
Laughing ; IV. Toys and Playthings ; 
V. Folk-Lore Among Children ; 
VJ. Early Forms of Vocal Expres- 
sion; vn. The Early Sense of Self; 
Vin. Fears in Childhood and Youth; 

IX. Some Common Traits and Habits; 

X. Some Common Automatisms, 
Nerve Signs, etc. ; XL Feeling for Ob- 
jects of Inanimate Nature ; XII. Feel- 
ing for Objects of Animate Nature ; 

XIII. Children's Appetites and Foods ; 

XIV. Affection and its Opposite States 
in Children ; XV. Moral and Religious 
Experiences. 

Laboratory of the McLean Hospital, 
SomerviUe, Mass. Am. Jour, of In- 
sanity, Jan., 1895, Vol. 51, pp. 358- 
364. 

Psychic Research. Am. Jour, of Psy., 
Oct., 1895, Vol. 7, pp. 1.35-142. 

Results of Child-study applied to Educa- 
tion. Trans. III. Soc. for Child-study, 
1895, Vol. 1, No. 4, p. 13. 

Introduction to the Psychology of Child- 
hood. By Frederick Tracy. Boston, 
1895. 

Address at Union College Centennial An- 
niversary, June 24, 1895. Printed by 
the College. N. Y., 1897, pp. 230-244. 



Published Papers. 



499 



Topical Syllabi for 1895-96. I. Peculiar 
and Exceptional Children, with E. W. 
Bohannon ; II. Moral Defects and 
Perversions, with Gr. E. Dawson ; III. 
The Beginnings of Reading and Writ- 
ing, with Dr. H. T. Lukens ; IV. 
Thoughts and Feelings about Old Age, 
Disease, and Death, with C. A. Scott ; 
V. Moral Education, with N. P. 
Avery ; VI. Studies of School Read- 
ing Matter, with J. C. Shaw; VII. 
Courses of Study in Elementary Gram- 
mar and High Schools, with T. R. 
Crosswell; VIII. Early Musical Mani- 
festations, with Florence Marsh; IX. 
Fancy, Imagination, Reverie, with E. 
H. Lindley; X. Tickling, Fun, Wit, 
Humor, Laughing, with Dr. Arthur 
Allin ; XI. Suggestion and Imitation, 
with M. H. Small ; XII. Religious 
Experience, with E. E. Starbuck ; 

XIII. Kindergarten, with Miss Anna 
E. Bryan and Miss Lucy Wheelock ; 

XIV. Habits, Instincts, etc., in Ani- 
mals, with Dr. R. R. Gurley ; XV. 
Number and Mathematics, with D. E. 
Phillips; XVI. The Only Child in 
the Family, with E. W. Bohannon. 

The Case of the Public Schools. Atlantic 
Monthly, March, 1896, Vol. 77, pp. 
402-413. 

Psychological Education. Proc. of the 
Am. Medico-Psychological Ass^n. 52d 
Annual Meeting, Boston, May 26-29, 
1896, Transactions, Vol. 3, pp. 87- 
100 ; also, Am. Jour, of Insanity, Oct. 
1896, Vol. 53, pp. 228-241. 

Generalizations and Directions for Child- 
study. Northwestern Jour, of Ed., 
July, 1896, Vol. 7, p. 8- 

Address at Mount Holyoke College, 
Founder's Day, Nov. 5, 1896. Mount 
Bolyoke, S. Hadley, Mass. Nov., 1896, 
Vol. 6, pp. 64-71. 

A Study of Dolls. (With A. C. Ellis.) 
Pedagogical Seminary, Dec, 1896. 
Vol. 4, pp. 129-175. Reprint, E. L. 
Kellogg & Co., N. Y., 1897. 69 pp. 

Nature Study. Proc. N. E. A., 1896. 
pp. 156-158. 

The Methods, Status, and Prospects of the 



Child-study of To-day. Trans. III. 
Soc. for Child-study, May, 1896, Vol. 
2, pp. 178-191. 

Topical Syllabi for 1896-97. L Degrees of 
Certainty and Conviction in Children, 
with Maurice H. Small ; II. Sabbath 
and Worship in General, with J. P. 
Hylan; III. Migrations, Tramps, 
Truancy, Running Away, etc., vs. 
Love of Home, with L. W. Kline ; IV. 
Adolescence, and its Phenomena in 
Body and Mind, with E. C. Lancaster ; 
V. Examinations and Recitations, with 
John C. Shaw ; VI. Stillness, Solitude, 
Restlessness, with H. S. Curtis ; VII. 
The Psychology of Health and Disease, 
with Henry H. Goddard ; VIII. Spon- 
taneously Invented Toys and Amuse- 
ments, with T. R. CrossweU; IX. 
Hymns and Sacred Music, with Rev. 
T. R. Peede ; X. Puzzles and their 
Psychology, with Earnest H. Lindley ; 
XI. The Sermon, with Rev. Alva R. 
Scott ; XII. Special Traits as Indices 
of Character and as Mediating Likes 
and Dislikes, with E. W. Bohannon ; 
XIII. Reverie and Allied Phenomena, 
with G. E. Partridge ; XIV. The Psy- 
chology of Health and Disease, with H. 
H. Goddard. 

A Study of Fears. Am. Jour, of Psy., 
Jan., 1897, Vol. 8, pp. 147-249. 

Some Practical Results of Child-study. 
First National Congress of Mothers, 
Washington, D. C, 1897. D. Apple- 
ton and Co., New York, 1897. pp. 
165-171. 

The Psychology of Tickling, Laughing, and 
the Comic. (With Arthur AUin.) Am. 
Jour, of Psy., Oct., 1897, Vol. 9, pp. 
1-41. 

Topical Syllabi for 1897-98. I. Immortal- 
ity, with J. Richard Street ; II. Psy- 
chology of Ownership vs. Loss, with 
Linus W. Kline ; III. Memory, with 
F. W. Colegrove ; IV. Humorous and 
Cranky Side in Education, with L. W. 
Kline ; V. The Psychology of Short- 
hand Writing, with J. O. Quantz ; VI. 
The Teaching Instinct, with D. E. 
Phillips ; VII. Home and School Pun- 



500 



Titles of 



ishments and Penalties, with Chas. 
H. Sears; VIII. Straightness and 
Uprightness of Body ; IX. Conven- 
tionality, with Albert Schinz ; X. 
Local Voluntary Association among 
Teachers, with Henry D. Sheldon ; 
XI. Motor Education, with E. W. 
Bohannon ; XII. Heat and Cold ; 
Xin. Training of Teachers, with 
W. G. Chambers ; XIV. Educational 
Ideals, with Lewis Edwin York ; XV. 
Water Psychoses, with Frederick E. 
Bolton; XVI. The Institutional Ac- 
tivities of Children, with Henry D. 
Sheldon ; XVII. Obedience and Obsti- 
nacy, with Tilmon Jenkins ; XVIII. 
The Sense of Honor Among Children, 
with Robert Clark. 

Some Aspects of the Early Sense of Self. 
Am. Jour, of Psy., April, 1898, Vol. 9, 
pp. 351-395. 

Initiations into Adolescence. Proc. of 
Am. Antiq. Soc, Worcester, Mass., 
Oct. 21, 1898, N. S. Vol. 12, p. 367- 
400. 

The Love and Study of Nature : A Part of 
Education. Agricultzire of Massachu- 
setts, for 1898, pp. 134-154. 

Topical Syllabi for 1898-99. I. The Organ- 
izations of American Student Life, with 
Henry D. Sheldon ; II. Mathematics 
in Common Schools, with E. B. Bryan ; 
III. Mathematics in the Early Years, 
with E. B. Bryan ; IV. Unselfishness 
in Children, with Willard S. Small ; 
V. The Fooling Impulse in Man and 
Animals, with Normal Triplett ; VI. 
Confession, with Erwin W. Kunkle ; 
VII. Pity; VIII. Perception of 
Rhythm by Children, with Chas. H. 
Sears. 

R6sum6 of Child-study. Northwestern 
Monthly, March-April, 1899, Vol. 9, 
pp. 347-349. Paidologist, Chelten- 
ham, Eng., April, 1899, Vol. l.pp. 5-8 

The Kindergarten. School and Home 
Education, Bloomington, HI., June 
1899, Vol. 18, pp. 507-509. 

A Study of Anger. Am. Jour, of Psy. 
July, 1899, Vol. 10, pp. 516-591. 

The Line of Educational Advance. Out- 



look, Aug. 5, 1899, Vol. 62, pp. 768- 
770. 

T. PROCTOR HALL: — 

B. A., University of Toronto, 1882; Fel- 
low and Instructor in Chemistry, ibid., 
1883-84; B.A., McMaster University, 
Toronto, 1894; M.A., and Ph.D., Illi- 
nois Wesleyan University, 1888 ; Science 
Master, Woodstock College, Woodstock, 
Ont., 1885-90 ; FeUow in Physics, 
Clark University, 1890-93 ; Ph.D., 
Clark University, 1893 ; Professor of 
Natural Sciences, Tabor College, Iowa, 
1893-96 ; Professor of Physics, Kansas 
City University, 1898- ; President Society 
of Economics, Kansas City ; Vice-Presi- 
dent Ex-Canadian Society, Kansas City. 

Author of : — 

The Projection of Four-fold Figures upon 
a Three-flat. Am. Jour, of Math., 
April, 1893, Vol. 15, pp. 179-189. 

The Possibility of a Realization of Four- 
fold Space. Science, May 13, 1892. 

New Methods of Measuring the Surface 
Tension of Liquids. Philosophical 
Magazine, Nov., 1893, Vol. 36, pp. 
385-413. 

Graphic Representation of the Properties 
of the Elements. Proc. Iowa Acad, 
of Set, 1894. 

A Mad-Stone. Ibid., 1895. 

Physical Theories of Gravitation. Ibid., 
1895. 

Unit Systems and Dimensions. Electrical 
World, Feb. 7, 1896. 

A Physical Theory of Electricity and 
Magnetism. Ibid., July 3, 1897, Vol. 
30, pp. 10-12. 

The Vortex Theory of Electricity and 
Magnetism. Home Study for Elec- 
trical Workers, Sept., 1898, pp. 34-36. 

Complex Algebra of the Plane Extended 
to Three-fold Space. Proc. Iowa Acad, 
of Sci., 1898, Vol.6. 

JOHN A. HANCOCK: — 

B.S., Baker University, 1877; Principal 
of Schools, Indiana and Wisconsin, 1877- 
89 ; Graduate Student in Pedagogy, Uni- 



Published Papers. 



501 



versity of Wisconsin, 1889-90; M.L., 
ibid. , 1890 ; City Superintendent, Green 
Bay, Wis., 1890-92 ; Graduate Student 
in Pedagogy, Leland Stanford Jr. Univer- 
sity, 1892-93 ; M.A., ibid., 189.3 ; FeUow 
in Pedagogy, Clark University, 1893- 
94 ; Superintendent of Schools, Durango, 
Col. , 1894-97 ; Temporary Assistant Pro- 
fessor of Psychology, University of Colo- 
rado, 1897-98 ; Superintendent of Schools, 
Santa Barbara, Cal., 1899-. 

Author of: — 

Secularization of Education. Wis. Jour. 

of Ed., March, 1890. 
Preliminary Study of Motor Ability. 

Pedagogical Seminary, Oct., 1894, Vol. 

3, pp. 9-29. 

The Kindergarten and Child Study. Col. 
School Jour., Feb., 1895. 

The Relation of Strength to Flexibility in 
the Hands of Men and Children. Peda- 
gogical Seminary, Oct., 1895, Vol. 3, 
pp. 308-313. 

Children's Ability to Reason. Educa- 
tional Review, Oct., 1896, Vol. 12, pp. 
261-268. 

An Early Phase of the Manual Training 
Movement — the Manual Labor School. 
Pedagogical Seminary, Oct., 1897, Vol. 
5, pp. 287-292. 

Mental Difierences of School Children. 
Proc. N. E. A., 1897, pp. 851-857. 

Children's Tendencies in the Use of Writ- 
ten Language Forms. Northwestern 
Monthly, June, 1898, Vol. 8, pp. 646- 
649. 

ROLLIN A. HARRIS: — 

Ph.B., Cornell University, 1885; Fellow 
in Mathematics, ibid., 1886-87 ; Ph.D., 
ibid., 1888 ; FeUow in Mathematics, 
Clark University, 1889-90 ; Computer, 
United States Coast and Geodetic Survey, 
Washington, D.C., 1890-. 

Author of : — 

The Theory of Images in the Eepresentar 
tion of Functions. Annals of Math., 
1888, Vol. 4, pp. 65-86, 128. 

On the Expansion of sn$. Ibid., Vol. 

4, pp. 87-90. 



Design for a Conicograph. Scien. Am. 
Supp., 1890, No. 740. 

On the Invariant Criteria for the Reality 
of the Roots of the Quintic. Annals 
of Math., 1891, Vol. 5, pp. 219-228. 

On Certain Bicircular Quartics Analogous 
to Cassini's Oval. Mathematical Maga- 
zine, Vol. 2, pp. 77-79. 

Note on Isogonal Transformations ; Par- 
ticularly on obtaining Certain Systems 
of Curves which Occur in the Statics 
of Polynomials. Annals of Math., 
1891, Vol. 6, pp. 77-80. 

Note on the Use of Supplementary Curves 
in Isogonal Transformation. Am. 
Jour, of Math., 1892, Vol. 14, pp. 291- 
300. 

Some Connections between Harmonic and 
Non-harmonic Quantities.Including Ap- 
plications to the Reduction and Predic- 
tion of Tides. U. S. Coast and Geod. 
Sur. Report, 1894, Appendix, No. 7 
(Manual of Tides, Part III.). 

Introduction and Historical Treatment of 
the Subject, Ibid., 1897, Appendix, 
No. 8 (Manual of Tides, Part I.). 

Tidal Observation, Equilibrium Theory, 
and the Harmonic Analysis, Ibid., 
1897, Appendix, No. 9 (Manual of 
Tides, Part 11.). 

A Proposed Tidal Analyzer. Physical 
Beview, 1899, Vol. 8, pp. 54-60. 

JAMBS N. HART: — 

B.C.E., Maine State College, 1885; Prin- 
cipal of High School, Dennysville, Me., 
1885 ; Instructor in Mathematics and 
Drawing, Maine State College, 1887-90; 
C.E., ibid., 1890 ; Scholar in Mathe- 
matics, Clark University, 1890-91 ; 
Professor of Mathematics and Astronomy, 
University of Maine, 1891-; Graduate Stu- 
dent in Mathematics and Astronomy, Uni- 
versity of Chicago, 1894-95; M.S., ibid., 
1897 ; Member of American Mathematical 
Society. 

S. B. HASLBTT: — 

Graduate, Edinboro, Pa., State Normal 
School, 1885 ; Principal, Creighton Pub- 
lic Schools, 1887-88; A.B., Grove City 



502 



Titles of 



College, Pa., 1889; Principal, Braddock 
High School, 1891-92 ; Graduate, Alle- 
gheny Theological Seminary, 1892 ; Pres- 
byterian Ministry, 1892-; A.M., Grove 
City College, 1896 ; Scholar in Psy- 
chology, Clark University, 1898-99. 

N. B. HELLER: — 

B.S., University of Pennsylvania, 1884; 
Professor of Mathematics, Boys' High 
School, Beading, Pa., 1887-91 ; Scholar 
in Mathematics, Clark University, 
1891-92 ; Fellow in Mathematics, Uni- 
versity of Chicago, 1892-93 ; Assistant 
Professor in Mathematics, Drexel Insti- 
tute, Philadelphia, 1893-. 

CLARK VTILSON HETHBRINGTON : 

A.B., Leland Stanford Jr. University, 
1895 ; Instructor, Enoina Gymnasium, 
Stanford University, 1893-96; Statistician 
and Director of Physical Training, Whit- 
tier State Eeform School, 1896-98 ; Fel- 
low in Psychology, Clark University, 
1898-99. 

JOHN E. HILL : — 

Ph.B., Sheffield Scientific School (Yale), 
1885 ; Resident Engineer, C. M. and St. 
Paul E.R., 1885-88; Professor of Mathe- 
matics, Military Academy, Louisville, 
Ky., 1888-89 ; Superintendent of Schools, 
Pleasantville, N. Y., 1889-90; Professor 
of Mathematics and Civil Engineering, 
Highland Park College, 1890-92 ; FeUow 
in Mathematics, Clark University, 
1892-95; Ph.D., Clark University, 
1895; Tutor in Mathematics, Columbia 
University, 1895-97 ; Teacher of Mathe- 
matics, Manual Training High School, 
Brooklyn, N. Y., 1897-98 ; Teacher of 
Science, High School, Stamford, Ct., 
1898-99. 

Author of : — 

On Quintic Surfaces. Mathematical Be- 

vieio, July, 1896, Vol. 1, pp. 1-59. 
Bibliography of Surfaces and Twisted 

Curves. Bull. Am. Math. Soc, Jan., 

1897, Vol. 3, pp. 133-146. 
On Three Septic Surfaces. Am. Jour, of 

Math., Oct., 1897, Vol. 19, pp. 289-311. 



BENJAMIN C. HINDB : — 

A.B., Central College, Missouri, 1881; 
A.M., ibid., 1882; Instructor in Physical 
Sciences, Howard College, 1882-88 ; Grad- 
uate Student, Johns Hopkins University, 
1888-90 ; Professor of Physics and Chem- 
istry, State Normal College, Mo., 1890-91 ; 
Professor of Physics, Trinity College, N. 
C, 1891-92; Fellow and Assistant in 
Physics, Clark University, 1892-93; 
Professor of Physics, Trinity College, 
N. C, 1893-94. 
Died Feb. 6, 1894. 

CLIFTON F. HODGE: — 

A.B., Eipon College, 1882; Civil En- 
gineer, Montana, 1882-86 ; Graduate Stu- 
dent, Johns Hopkins University, 1886-88 ; 
Fellow in Biology, ibid., 1888-89 ; Ph.D., 
Johns Hopkins University, 1889 ; Fellow 
in Psychology and Assistant in Neu- 
rology, Clark University, 1889-91 ; 
Instructor in Biology, University of Wis- 
consin, 1891-92 ; Assistant Professor 
of Physiology and Neurology, Clark 
University, 1892- ; Member of : Ameri- 
can Physiological Society, Society Ameri- 
can Naturalists, Massachusetts Forestry 
Association, Boston Society of Medical 
Sciences. 

Author of : — 

Some Effects of Stimulating Ganglion 
Cells. Am. Jour, of Psy., May, 1888, 
Vol. 1, pp. 479-486. 

Some Effects of Electrically Stimulating 
Ganglion Cells. Ibid. , May, 1889, Vol. 
2, pp. 376-402. 

A Study of the Oyster Beds of Long 
Island Sound with Reference to the 
Ravages of Starfish. J. H. U. Circular, 
Sept., 1889, No. 75, Vol. 8, p. 102. 

A Sketch of the History of Reflex Action. 
Am. Jour, of Psy., April and Sept., 
1890, Vol. 3, pp. 149-167, 343-363. 

The Process of Recovery from the Fatigue 
occasioned by the Electrical Stimula- 
tion of Cells of the Spinal Ganglia. 
Ibid., Feb., 1891, Vol. 3, pp. 530- 
643. 

Homing Pigeons, .^gis, June, 1892. 



Published Papers. 



503 



A Microscopical Study of Changes due to 
Functional Aotiyity in Nerve Cells. 
Jour, of Morph., Nov., 1892, Vol. 7, 
pp. 95-168. 

The Method of Homing Pigeons. Pop. 
Sci. Mo., April, 1894, Vol. 44, pp. 
758-775. 

Changes in Ganglion Cells from Birth to 
Senile Death. Observations on Man 
and Honeybee. Jour, of Phys., 1894, 
Vol. 17, pp. 129-134. 

Botanical Gardens. Wor. Co. Hort. Soc. 
Sep., 1894-95, pp. 102-117. 

Die Nervenzelle bei der Geburt und beim 
Tode an Alterschwache. Anat. An- 
zeiger, Aug. 1, 1894, Vol. 9, pp. 706- 
710. 

A Microscopical Study of the Nerve Cell 
during Electrical Stimulation. Jour, 
of Morph., Sept., 1894, Vol. 9, pp. 
449-463. 

The Daily Life of a Protozoan : A Study 
in Comparative Psycho-Physiology. 
(With H. A. Aikins.) Am. Jour, of 
Psy., Jan., 1895, Vol. 6, pp. 524-533. 

The Vivisection Question. Pop. Sci. Mo., 
Sept. and Oct., 1896, Vol. 49, pp. 614- 
624, 771-785. 

Experiments on the Physiology of Alcohol, 
made under the Auspices of the Com- 
mittee of Fifty. Ibid., March and 
April, 1897, Vol. 50, pp. 594-603, 
796-812. 

Horticultural Interests in Relation to 
Public Education. Wor. Co. Hort. 
Soc. Mep., 1898, pp. 62-81. 

The Common Toad. Nature Study Leaf- 
let. Biology Series, No. 1, 1898. 
Worcester, Mass. 15 pp. 

Our Common Birds. Biology Series, No. 
2, 1899. Worcester, Mass. 34 pp. 

FREDERICK H. HODGE: — 

A.B., Boston University, 1894; A.M., 
ibid., 1899 ; Special Student, Bridgewater 
Normal School, 1894-95 ; Professor of 
Mathematics, J. B. Stetson University, 
1895-96 ; Graduate Student in Mathe- 
matics, University of Chicago, 1896-97 ; 
Scholar in Mathematics, Clark Uni- 
versity, 1897-98 ; Fellow, 1898-99 ; 



Professor of Mathematics and History, 
Bethel College, Russell ville, Ky., 1899-. 

THOMAS FRANKLIN HOLGATE: — 

B. A., Victoria University, Toronto, 1884 ; 
Mathematical Master, Albert College, 
Belleville, Ont., 1884-90; M.A., Victoria 
University, 1889 ; Fellow in Mathe- 
matics, Clark University, 1890-93 ; 
Ph.D., Clark University, 1893; In- 
structor in Mathematics, Northwestern 
University, 1893-94 ; Professor of Ap- 
plied Mathematics, ibid., 1894- ; Member 
of the American Mathematical Society. 

Author of : — 

On the Cone of the Second Order which 
is Analogous to the Nine Point Conic. 
Aimals of Math., 1893, Vol. 7, pp. 
73-76. 

On Certain Ruled Surfaces of the Fourth 
Order. Am. Jour, of Math., Oct., 
1893, Vol. 15, pp. 344-386. Addi- 
tional Note on same. Ibid. (In 
press.) 

Correction of an Error in Salmon's " Ge- 
ometry of Three Dimensions." Bull. 
N. T. Math. Soc, 1894, Vol. 3, p. 224. 

A Geometrical Locus connected with a 
System of Coaxial Circles. Bull. Am. 
Math. Soc, Nov., 1897, 2d ser., Vol. 
4, pp. 63-67. 

A Second Locus connected with a System 
of Coaxial Circles. Ibid., Dec, 1898, 
Vol. 5, pp. 135-143. 

Reye's "Lectures on the Geometry of 
Position" (translation). Part I. Mac- 
millan Company, New York, 1898. 
248 pp. 

RICHARD J. HOLLAND: — 

B.A., Victoria College, Toronto, 1887 ; 
Certificate Specialist in Science, Teachers' 
Training Institute, Kingston, Ont., 1887- 
88 ; Science Master, Morrisburg Collegiate 
Institute, 1888-90 ; Graduate Student, Uni- 
versity of Leipzig, 1890-93 ; Ph.D., Uni- 
versity of Leipzig, 1893 ; Honorary 
Fellow in Physics, Clark University, 
1893-94 ; with Westinghouse Electric 
Company, Pittsburg, Pa., 1894-95; with 



504 



Titles of 



Electric Power Storage Company, N. Y. 
City, April, 1896-. 

Author of : — 

Ueber die Aenderung der electrisclien 
Leitfahigkeit einer Losung durch Zu- 
satz von kleinen Mengen eines Nicht- 
leiters. Wied. Annalen, Sept., 1893, 
Vol. 50, pp. 261-292. 

Ueber die electrische Leitfahigkeit von 
Kupferchloridlosungen. Ibid., pp. 349- 
360. 

R. C. HOLLENBAUGH : — 

A.B., Bucknell University, 1888; Princi- 
pal, Cross Creek Academy, 1888-89 ; 
A.M., Bucknell University, 1891; Ph.D., 
Wooster University, 1891 ; Graduate Stu- 
dent, Johns Hopkins University, 1891-92 ; 
Scholar in Psychology, Clark Univer- 
sity, 1892. 
Died July 6, 1893. 

■WILLIAM A. HOYT: — 

A.B., Bates College, 1880; Principal 
High School, Rockport, Me., 1881-82; 
Principal Greeley Institute, Cumberland, 
Me., 1882-88 ; Cornwall Heights School, 
Cornwall, N. Y., 1883-86; A.M., Bates 
College, 1884; Principal High School : Med- 
way, Mass., 1886-88, North Brookfield, 
Mass., 1888-92, Augusta, Me., 1892-93; 
Scholar in Pedagogy, Clark Universi- 
ty, 1893-94 ; Superintendent of Schools, 
Brookfield, Mass. (District), 1894-. 

Author of : — 

The Love of Nature as the Boot of Teach- 
ing and Learning the Sciences. Peda- 
gogical Seminary, Oct., 1894, Vol. 3, 
pp. 61-86. 

EDMUND B. HUEY: — 

A.B., Lafayette College (First Honors 
inPhilosophy and Anglo-Saxon), 1895; In- 
structor in Latin, Harry Hillman Academy, 
Wilkesbarre, Pa., 1896-97 ; Scholar in 
Psychology, Clark University, 1897- 
98; Fellow, 1898-99; Professor of Psy- 
chology, State Normal School, Moor- 
head, Minn., I899-. 



Author of: — 

Preliminary Experiments in the Physi- 
ology and Psychology of Beading. 
Am. Jour, of Psy., July, 1898, Vol. 9, 
pp. 575-586. 

D. D. HUGH : — 

A.B., Dalhousie College, 1891; A.B., 
Harvard University, 1892 ; A.M., Cornell 
University, 1893 ; Fellow in Psychol- 
ogy, Clark University, 1895-96 ; Prin- 
cipal of High School, La Junta, Col., 
1896-98; Professor of Psychology, Colo- 
rado State Normal School, Greeley, Col., 
1898-99 ; Professor of Pedagogy and Eng- 
lish, State Agricultural College, Logan, 
Utah, 1899-. 
Author of : — 

Formal Education fiom the Standpoint of 
Physiological Psychology. Pedagogi- 
cal Seminary, April, 1898, Vol. 5, 
pp. 599-605. 
The Animism of Children. Northwestern 
3Ionthly, June, 1899, Vol. 9, pp. 450- 
453. 

LOHRAIN S. HULBURT: — 

A.B., University of Wisconsin, 1883 ; A.M., 
ibid., 1888; Professor of Mathematics, 
University of So. Dakota, 1887-91 ; Grad- 
uate Student, University of Gottingen, 
1889-90 ; Fellow inMathematics, Clark 
University, 1891-92 ; Instructor in 
Mathematics, Johns Hopkins University, 
1892-94 ; Ph.D., Johns Hopkins Univer- 
sity, 1894 ; Associate in Mathematics, 
ibid., 1894-97 ; Collegiate Professor of 
Mathematics, ibid., 1897- ; Member of 
American Mathematical Society. 
Author of : — 

Theorems on the Number and Arrange- 
ment of the Beal Branches of Plane 
Algebraic Curves. Am. Jour, of Math., 
July, 1892, Vol. 14, pp. 246-250. 
Topology of Algebraic Curves. Bull, of 
the N. Y. Math. Soc, 1892, Vol. 1, 
pp. 197-202. 

JOHN L HUTCHINSON: — 

A.B., Bates College, 1889; Scholar in 
Mathematics, Clark University, 1890- 



Published Papers. 



505 



91 ; Fellow, 1891-92 ; Fellow in Mathe- 
matics, University of Chicago, 1892-94 ; 
Instructor in Mathematics, Cornell Uni- 
versity, 1894- ; Ph.D., University of 
Chicago, 1896 ; Member of American 
Mathematical Society. 

Author of : — 

A Special Form of a Quartic Surface, 
Annals of Math., June, 1897, Vol. 2, 
pp. 158-160. 

On the Reduction of Hyperelliptio Func- 
tions, {p = 2) to Elliptic Functions by a 
Transformation of the Second Degree. 
(Dissertation.) Gottingen, 1897. 40 pp. 

Note on the Tetrahedroid. Bull, of the 
Am. Math. Soc, April, 1898, 2d ser., 
Vol. 4, pp. 327-329. 

The Hessian of the Cubic Surface. Ibid., 
March, 1899, 2d ser., Vol. 5, pp. 282- 
292. 

The Asymptotic Lines of the Kummer 
Surface. Ibid., July, 1899, 2d ser.. 
Vol. 5, pp. 465-467. 

JOHN P. HYLAN : — 

Student, Harvard University, 1891-95 ; 
Fellow in Psychology, Clark Univer- 
sity, 1895-97 ; Instructor in Psychology, 
University of Illinois, 1897-98 ; Assistant 
Professor, ibid., 1898-99; Member of 
Executive Commission of Illinois Society 
of Child Study. 

Author of : — 

Fluctuation of Attention. (Studies from 
the Harvard Psy. Lab.) Psychological 
Review, Jan., 1896, Vol. 3, pp. 56-63. 

The Fluctuation of Attention. Psycho- 
logical Bemevi, Monograph Supple- 
ment, March, 1898, Vol. 2, No. 2. 
78 pp. 

MASSUO IKUTA: — 

Student, University of Tokio, Japan, 1880- 
85 ; University of Berlin, 1886 ; University 
of Erlangen, 1887-88; Ph.D., University 
of Erlangen, 1888 ; Consulting Chemist, 
Tokio, Japan, 1889-90 ; Assistant in 
Chemistry, Clark University, 1890- 
92 ; Assistant in Chemistry, University of 
Chicago, 1892-95 ; Instructor, ibid., 1895-. 



Author of : — 

Ueber die Einwirkung von Acetessigather 
auf Chinone ; Synthese von Benzofur- 
furan-Derivaten. Jour, fur praktische 
Chemie, 1892, Vol. 45, pp. 65-83. 

Metamidophenol and its Derivatives, Am. 
Chem. Jour., Jan., 1893, Vol. 15, pp. 
39-44. 

JAMBS EDMUND IVES: — 

Je.ssup Student, Academy of Natural 
Sciences, 1887-91 ; Assistant Curator, 
ibid. , 1887-93 ; Instructor in Physics, 
Drexel Institute, 1893-97 ; Student in 
Histology and Embryology, University of 
Pennsylvania, 1888-89 ; Student in Mathe- 
matics, ifticZ. , 1893-95; Student in Physics, 
Cavendish Laboratory, Cambridge, Eng., 
1896 ; Scholar in Physics, Clark Uni- 
versity, 1897-98 ; FeUow, 1898-99. 

Author of : — 

On Two New Species of Starfishes. Proc. 

Acad. Nat. Sci. of Phila., 1888, pp. 

421-424. 
Linguatula Diesingii, from the Sooty 

Mangabey. Ibid., 1889, p. 31. 
Variation in Ophiura Panamensis and 

Ophiura teres. Ibid., 1889, pp. 76- 

77. 
On a New Genus and Two New Species of 

Ophiurans. Ibid., 1889, pp. 143-145. 
Catalogue of the Asteroidea and Ophiuroi- 

dea in the Collection of the Academy 

of Natural Sciences of Philadelphia. 

Ibid., 1889, pp. 169-179. 
Mimicry of the Environment in Ptero- 

phryne histrio. Ibid., 1889, pp. 344- 

345. 
On Arenicola cristata and Its Allies. 

Ibid., 1890, pp. 73-75. 
Echinoderms from the Northern Coast of 

Yucatan and the Harbor of Vera Cruz. 

Ibid., 1890, pp. 317-340. 
Crustacea from the Northern Coast of 

Yucatan, the Harbor of Vera Cruz, 

the West Coast of Florida and the 

Bermuda Islands. Ibid., 1891, pp. 

176-207. 
Echinoderms and Arthropods from Japan. 

Ibid., 1891, pp. 210-223. 



506 



Titles of 



Echinoderms from the Bahama Islands. 
Ihid., 1891, pp. 337-341. 

Beptiles and Batrachians from Northern 
Yucatan and Mexico. 76Jd, 1891, pp. 
458-463. 

Echinoderms and Crustaceans collected by 
the West Greenland Expedition of 1891. 
Ihid., 1891, pp. 479-481. 

A New Species of Pyonogonum from Cali- 
fornia. Ibid., 1892, pp. 142-144. 

TILMON JENKINS: — 

B.A., National Normal University, 1882 ; 
Professor of Didactics, Salina, Kan., 
Normal University, 1883-85 ; Superin- 
tendent of Schools, Kingman, Kan. , 1885- 
87; M.A., National Normal University, 
1891 ; Educational work in Colorado, 
1887-96 ; Assistant State Superintendent 
of Public Instruction, Colorado, 1894 ; 
Superintendent of Schools, Santa F6, New 
Mexico, 1896-97 ; Scholar in Pedagogy, 
Clark University, 1897-98 ; Special 
Student, University of Colorado, 1898-99. 

GEORGE EI,LS"WOHTH JOHNSON: — 

A.B., Dartmouth College, 1887; A.M., 
ibid. 1891 ; Principal, Colebrook Acad- 
emy, N. H., 1887-88 ; Principal of Schools, 
Springfield, Vt., 1888-92 ; Student, Hart- 
ford Theological Seminary, 1892-93; 
Scholar in Pedagogy, Clark Univer- 
sity, 1893-94 ; FeUow, 1894-95 ; Su- 
perintendent of Schools, Andover, Mass., 
1895-. 

Author of : — 

Education by Plays and Games. Peda- 
gogical Seminary, Oct., 1894, Vol. 3, 
pp. 97-133. 

Contribution to the Psychology and Peda- 
gogy of Feeble-minded Children. Ibid., 
Oct., 1895, Vol. 3, pp. 246-301. 

Play in Education. Northwestern Monthly, 
July, 1897, Vol. 8, pp. 3-8. 

Games and Play. First of Series of 
Twelve Monographs on Social Work. 
Issued by Lincoln House, Boston, 
Mass., and The Commons, Chicago, 
111. The Co-operative Press, Cam- 
bridge, 1898. 22 pp. 



Play in Physical Education. Am. Phys. 
Ed. Rev., Sept., 1898, Vol. 3, pp. 179- 
187. 

The New Education. Address delivered 
before the Andover Burns Club, 
March 19, 1898. The Andover Press, 
Andover, Mass., 1898. 15 pp. 

HERBERT P. JOHNSON: — 

A.B., Harvard University (with Honors 
in Natural History), 1889; A.M., ihid., 
1890 ; Assistant in Biology, AVilliams Col- 
lege, 1890-91 ; Fello'W in Morphology, 
Clark University, 1891-92 ; Fellow in 
Morphology, University of Chicago, 1892- 
94 ; Ph.D., University of Chicago, 1894 ; 
Instructor in Biology, Des Moines Col- 
lege, 1894 ; Assistant Professor of Zo- 
ology, University of California, 1894- ; 
Member of : American Society of Natu- 
ralists ; California Academy of Sciences ; 
San Francisco Microscopical Society. 

Author of : — 

Amitosis in the Embryonal Envelopes of 
the Scorpion. Bull. Museum Com- 
parative Zo'ol., Harvard College, 1892, 
Vol. 22, pp. 127-161 ; 3 pis. 

A Contribution to the Morphology and 
Biology of the Stentors. Jour, of 
Morph., Aug., 1893, Vol. 8, pp. 468- 
562 ; 4 pis. 

The Plastogamy of Actinosphaerium. 
Ibid. April, 1894, Vol. 9, pp. 269-276. 

A Preliminary Account of the Marine 
Annelids of the Pacific Coast, vdth 
Descriptions of New Species. Proc. 
California Academy of Sciences, Third 
Series. Zoology, 1897, Vol. 1, pp. 
153-198 ; 6 pis. 

ED"WIN O. JORDAN : — 

S.B., Massachusetts Institute of Tech- 
nology, 1888 ; Chief Assistant Biologist, 
Massachusetts State Board of Health, 
1888-90 ; Lecturer in Biology, Massachu- 
setts Institute of Technology, 1889-90 ; 
Fello-w in Morphology, Clark Uni- 
versity, 1890-92 ; Ph.D., Clark Uni- 
versity, 1892 ; Associate in Biology, 
University of Chicago, 1892-93 ; Instructor 



Published Papers. 



507 



in Biology, ibid., 1893-95 ; Assistant Pro- 
fessor of Bacteriology, ibid., 1895-. 

Author of : — 

Phagocytosis and Immunity, Boston 
Med. and Surg. Jour., 1890, Vol. 122, 
p. 406. 

Recent Theories on the Function of the 
"White Blood-Cell. Technology Quar- 
terly, 1890, Vol. 3, p. 170. 

Certain Species of Bacteria observed in 
Sewage. Report of the Mass. State 
Board of Health on Water Supply and 
Sewage, 1889-90, Vol. 2, p. 821. 

Investigations on Nitrification and the 
Nitrifying Organisms. (With Mrs. Ellen 
H. Richards.) Ibid., Vol. 2. Volume 
on Water Supply and Sewage, 1890, 
p. 865. 

The Spermatophores of Diemyctylus. 
Jour, of Morph., Sept., 1891, Vol. 5, 
pp. 263-270. 

The Cleavage of the Amphibian Ovum. 
(With A. C. Bycleshymer.) Anat. 
Ameiger, Sept. 15, 1892, Vol. 7, 
pp. 622-624. 

The Habits and Development of the Newt. 
Jour, of Morph., May, 1893, Vol. 8, 
pp. 270-366, 5 Plates. 

On the Cleavage of Amphibian Ova. (With 
A. C. Eycleshymer.) Ibid., Sept., 
1894, Vol. 9, pp. 407-416, 1 Plate. 

The Identification of the Typhoid Fever 
Bacillus. Jour. Am. Med. Ass''n, 
Dec. 22, 1894. 

On Some Conditions affecting the Be- 
havior of the Typhoid Bacillus in 
Water. Medical News, Sept. 28, 1895. 

The "Inheritance" of Certain Bacterial 
Diseases. Chicago Med. Recorder, 
Aug., 1898, Vol. 15, p. 82. 

The Production of Fluorescent Pigment by 
Bacteria. Botanical Gazette, Jan., 
1899, Vol. 27, p. 19. 

Translation of the Principles of Bacteri- 
ology by Professor F. Hueppe. Open 
Court Publishing Co., Chicago. 467 pp. 

The Death-rate from Diphtheria in the 
Large Cities of the United States. 
, Philadelphia Med. Jour., Feb. 18, 

1899. 



F. C. KENYON: — 

B.Sc, University of Nebraska, 1892 ; In- 
structor in Zoology, ibid., 1891-93 ; Assist- 
ant and Fellow in Biology, Tufts College, 
1893-95 ; A.M. and Ph.D., Tufts College, 
1895; Fellow in Biology, Clark Uni- 
versity, 1895-96 ; Fellow, American 
Association for the Advancement of 
Science ; Member of : American Morpho- 
logical Society, American Society of 
Naturalists, National Geographic Society. 

Author of : — 

The Morphology and Classification of the 
Pauropoda. Tufts College Studies, 
1895. 

In the Region of the New Fossil ; Dse- 
mouelix. American Naturalist, 1895. 

Formal as a Preserving Agent. Ibid., 
1895. 

The Meaning and Structure of the So- 
called Mushroom Bodies of the Hexa- 
pod Brain. Ibid., 1896. 

The Brain of the Bee. Jour. Camp. Neu- 
rology, 1896. 

The Optic Lobe of the Bee's Brain in the 
Light of Recent Neurological Methods. 
1897. 

Delarvation. American Naturalist, 1897. 

The Chartognaths of American Waters. 
Ibid. 

The Regeneration of an Antenna-like 
Structure instead of an Eye. Ibid. 

The Regeneration of the Lens of the Eye 
of Tritan. Ibid. 

Formol or Formalin. Ibid. 

Effect of Lithium Chloride upon the De- 
velopment of the Frog and Toad Egg. 
Ibid., 1896. 

The Terminology of the Neurocytes. 
Science, 1897. 

HERBERT G. KEPPEL: — 

A.B., Hope College, Holland, Mich., 
1889 ; Instructor in Mathematics, North- 
western Classical Academy, Orange City, 
la., 1891-92; Scholar in Mathematics, 
Clark University, 1892-93; Fellow, 
1893-95 ; Instructor in Mathematics, 
Academy of Northwestern University, 
Evanston, 111., 1895-96; Instructor in 



508 



Titles of 



Mathematics, Northwestern University, 
Bvanston, 111., 1896- ; Member of the 
American Mathematical Society ; Member 
of Het Wiskundig Genootschap, Amster- 
dam. 

E. A. KIRKPATRICK : — 

B.Sc, Iowa Agricultural College, 1887; 
M.Ph., Ibid., 1889; Scholar in Psy- 
chology, Clark University, 1889-90 ; 
Fellow, 1890-91; Professor of Psy- 
chology and Pedagogy, State Normal 
School, Winona, Minn., 1892-97 ; Pro- 
fessor of Psychology and Child Study, 
State Normal School, Fitchburg, Mass., 
1898- ; Member of American Psychologi- 
cal Association. 

Author of : — 

Observations on College Seniors and Elec- 
tives in Psychological Subjects. Am. 
Jour. ofPsy., April, 1890, Vol. 3, pp. 
168-173. 

Number of Words in an Ordinary Vocabu- 
lary. Science, Aug, 21, 1891, Vol. 18, 
pp. 107-108. 

How Children learn to Talk. Ibid., 
Sept. 25, 1891, Vol. 18, pp. 175-176. 

Mental Images. Ibid. , Oct. 27, 1893, Vol. 
22, pp. 227-230. 

An Experimental Study of Memory. Psy- 
chological Review, Nov., 1894, Vol. 1, 
pp. 602-609. 

Inductive Psychology: An Introduction 
to the Study of Mental Phenomena. 
E. L. Kellogg & Co., New York, 1896. 
208 pp. 

Child Study in the Training of Teachers. 
Review of Reviews, Dec, 1896, Vol. 
14, pp. 686-692. 

Handbook of Minnesota Child-Study As- 
sociation. James and Kroeger, Wi- 
nona, Minn., 1897. 60 pp. 

Continuous Sessions of Schools. Review 
of Reviews, July, 1897, Vol. 16, pp. 
190-191. 

Play as a Factor in Social and Educa- 
tional Reforms. Ibid., Aug., 1899, 
Vol. 20, pp. 192-196. 

Children's Reading. N'orthwestern Month- 
ly, June, 1898, Vol. 8. pp. 651-654; 



Dec, 1898, Jan., March-April, 1899, 
Vol. 9, pp. 188-191, 229-233, 338-342. 

Learning Voluntary Movements. School 
and Home Education, March, 1899, 
Vol. 18, pp. 337-344. 

The Development of Voluntary Move- 
ment. Psychological Review, May, 
1899, Vol. 6, pp. 275-281. 

MILTON S. KISTLER: — 

Graduate, West Chester, Pa., State Nor- 
mal School, 1888 ; Principal, High School, 
Honey Brook, Pa., 1888-89 ; Principal, 
Blaine Normal Institute, Pa., 1889-90 ; 
Ph.B., Dickinson College, 1894; A.M., 
ibid., 1897; Professor of Latin and Eng- 
lish, Edinboro, Pa., State Normal School, 
1894-97 ; Scholar in Pedagogy, Clark 
University, 1897-98; Teacher, N. Y. 
City Schools, 1898-. 

Author of : — 

John Knox's Services to Education. Edu- 
cation, Boston, Mass., Oct. 1898, Vol. 
19, pp. 105-116. 

LINUS -W. KLINE: — 

Student, University of Virginia, 1886-87 ; 
L.I., Peabody Normal College, 1889; 
Principal, Hamilton Grammar School, 
Houston, Texas, 1891-93 ; B.S., Harvard 
University, 1896 ; Scholar in Psychol- 
ogy, Clark University, 1896-97 ; Fel- 
low, 1897-98 ; Ph.D., Clark Univer- 
sity, 1898 ; Honorary FeUow and 
Assistant in Psychology, 1898-99 ; 
Professor of Psychology and Pedagogy, 
State Normal School, Mankato, Minn., 
1899-. 

Author of : — 

Truancy as Related to the Migrating In- 
stinct. Pedagogical Seminary, Jan., 
1898, Vol. 5, pp. 381-420. 

The Migratory Impulse vs. Love of Home. 
Am. Jour, of Psy., Oct. 1898, Vol. 10, 
pp. 1-81. 

Methods in Animal Psychology. Ibid., 
Jan., 1899, Vol. 10, pp. 2.56-279. 

Suggestions toward a Laboratory Course 
in Comparative Psychology. Ibid., 
April, 1899, Vol. 10, pp. 399-430. 



Published Papers. 



509 



The Psychology of Ownership. (With C. 
J. France.) Pedagogical Seminary. 
(In press.) 

■WILLIAM O. KHOHN: — 

A.B. , Western College, 1887 ; Ph.D., 
Yale University, 1889 ; Instructor in Phi- 
losophy and Psychology, Western Reserve 
University, 1889-91 ; Inspecting Psycho- 
logical Laboratories in German Universi- 
ties, July, 1891-Feb. 1892 ; Fellow in 
Psychology, Clark University, March- 
June, 1892 ; Professor of Psychology, 
University of Illinois, 1892-97 ; Psychol- 
ogist, Illinois Eastern Hospital, Kanka- 
kee, 111., 1897- ; Editor of Child-Study 
Monthly. 

Author oi : — 

Facilities in Experimental Psychology at 

the Various German Universities. Am. 

Jour, of Psy., Aug., 1892, Vol. 4, pp. 

585-594. 
Pseudo-Chromesthesia, or the Association 

of Colors with Words, Letters, and 

Sounds. Ibid., Oct., 1892, Vol. 5, pp. 

20-41. 
An Experimental Study of Simultaneous 

Stimulation of the Sense of Touch. 

Jour, of Nervoiis and Mental Disease, 

March, 1893 ; N. S., Vol. 18, pp. 169- 

184. 
Practical Lessons in Psychology. The 

Werner Co., Chicago and New York. 

400 pp. 
Laboratory Psychology as applied to the 

Study of Insanity. Psychiater, Vol. 1, 

No. 1. 
Minor Mental Abnormalities in Children 

as occasioned by Certain Erroneous 

School Methods. Proc. iV. E. A. , 1898, 

pp. 162-172. 

ELLSWORTH G. LANCASTER: — 

B.A., Amherst College, 1885; M.A., 
ibid. 1888 ; Teacher, Elocution and Phys- 
ical Culture, Williston Seminary, East- 
hampton, Mass., 1885-86; Student, 
Auburn Theological Seminary, 1886-87 ; 
Teacher, Physical Culture, Latin, and 
German, Morgan Park Military Academy, 



1887-88 ; Student, Chicago Baptist Semi- 
nary, 1887-88 ; Student, Andover Theo- 
logical Seminary, 1888-89; B.D., ibid., 
1889 ; Pastor, Congregational Church, 
Ashby, Mass., 1889-90 ; Principal, South- 
ern Kansas Academy, 1890-95 ; Scholar 
in Psychology, Clark University, 
1895-96; Fellow, 1896-97; Ph.D., 
Clark University, 1897 ; Instructor in 
Philosophy and Pedagogy, and President's 
Assistant, Colorado College, 1897-98; 
Assistant Professor, ibid., 1898-. 

Author of : — 

Psychology and Pedagogy of Adolescence. 

Pedagogical Seminary, July, 1897, 

Vol. 5, pp. 61-128. 
Warming Up. Colorado College Studies, 

Nov., 1898, Vol. 7, pp. 16-29. 

JAMES STEPHEN LEMON: — 

B.A., Wesleyan University, 1863; M.A., 
ibid., 1866; Principal of High School, 
Brownville, New York, 1862; Assistant on 
McClintock and Strong's Cyclopaedia of 
Biblical, Theological, and Ecclesiastical 
Literature, 1859-61 ; Assistant on Strong's 
Concordance of the Bible, 1859-65 ; Pro- 
fessor of Physios, Marion, N. Y., Institute, 
1863-65 ; Principal, Almond Collegiate In- 
stitute, 1866 ; Principal, Macedon, N. Y., 
Academy, 1867 ; Rector, Protestant Epis- 
copal Church, 1877-; Scholar in Psy- 
chology, Clark University, 1891-93 
Student in Psychology, 1893-94 ; Lec- 
turer in Psychophysics, Columbian Uni- 
versity, Washington, D.C., 1894-; Ph.D. 
Columbian University, 1896 ; Lecturer 
in Physiological Psychology, Howard 
University, 1897- ; Member Society for 
Philosophical Inquiry, Washington, D. C; 
Member American Anthropological So- 
ciety. 

Author of: — 

Signalling by Flashlights. Troy, Pa. , 1874. 

10 pp. 
The Body Considered in Its Relation to the 

Intellectual Processes. Union Springs, 

N. Y., 1875. 
Lists of Questions to be Asked as to 

Defectives, etc., admitted to Cottage 



510 



Titles of 



Hospitals for Children. Athol, Mass. 
7 pp. 

Psychic Effects of the Weather. Am. Jour. 
ofPsy., Jan., 1894, Vol. 6, pp. 277-311. 

Eequirements Demanded for Official Rec- 
ognition as Teachers. Templeton Press, 
Templeton, Mass., 1898. 13 pp. 

The Skin considered as an Organ of Sensa- 
tion. Journal Publishing Co., Gardner, 
Mass., 1898. 77 pp. 

The Weather Idea. Journal Publishing 
Co., Gardner, Mass., 1899. 60 pp. 

Numerous reviews and articles in Healthy 
Home, Cottager, and National Tribune, 
1880-. 

JAMES E. LEROSSIGNOL : — 

B.A.,McGill University, 1888; Teacher in 
Berthelet School, Montreal, 1888-89 ; Stu- 
dent in Philosophy, University of Leipzig, 
1889-92; Ph.D., University of Leipzig, 
1892; Fellow in Psychology, Clark Uni- 
versity, May-July, 1892 ; Professor of 
Psychology and Ethics, Ohio University, 
Athens, 1892-94; Professor of History and 
Political Economy, University of Denver, 
1894- ; Member of : American Economic 
Association, American Academy of Polit- 
ical and Social Science, American His- 
torical Association. 

Author of : — 

The Ethical Philosophy of Samuel Clarke. 

G. Kreysing, Leipzig, 1892. 97 pp. 
The Training of Animals. Am. Jour, of 

Psy., Nov., 1892, Vol. 5, pp. 205-213. 
Malevolence in the Lower Animals. Ohio 

University Bulletin, Sept., 1893, Vol. 1, 

pp. 1-9. 
The Expression of Anger. Transactions 

of the Ohio College Association, 1894, 

pp. 40-49. 
Spinoza as a Biblical Critic. Canadian 

Methodist Beview, Jan.-Peb., 1895, Vol. 

7, pp. 52-60. 

JAMES H. LETJBAr- 
B.S., University of NeuohStel, Switzer- 
land, 1886 ; Ph.B., Ursinus College, 1888 ; 
Instructor in French and German, St. 
Mark's School, Southborough, Mass., 



1891-92 ; Scholar in Psychology, Clark 
University, 1892-93; Fellow, 1893- 
95; Ph.D., Clark University, 1895; 

Professor of Psychology and Pedagogy, 
Bryn Mawr College, 1897- ; Universities 
of Leipzig, Gottingen, Heidelberg, and 
Paris, 1897-98 ; Member of the American 
Psychological Association. 

Author of : — 

A New Instrument for Weber's Law ; with 
Indications of a Law of Sense Memory. 
Am. Jour, of Psy., A-pvil, 1893, Vol. 5, 
pp. 370-384. 

National Destruction and Construction in 
France as seen in Modern Literature 
and in the Neo-Christian Movement. 
Ibid., July, 1893, Vol. 5, pp. 496-539. 

A Study in the Psychology of Religious 
Phenomena. Ibid., April, 1896, Vol. 
7, pp. 309-385. 

The Psycho-Physiology of the Moral Im- 
perative. Ibid., July, 1897, Vol. 8, pp. 
628-559. 

On the Validity of the Griesbach Method 
of Determining Fatigue. Psychologi- 
cal Review, Nov., 1899, Vol. 6, pp. 
573-598. 

FRANK R. LILLIE: — 

Assistant in Biology, University of Toronto, 
1890-91; B.A., ibid., 1891 ; Fellow in 
Morphology, Clark University, 1891- 
92; Fellow in Zoology, University of Chi- 
cago, 1892-93 ; Reader in Embryology, 
ibid., 1893-94; Ph.D., University of Chi- 
cago, 1894; Instructor in Zoology, Uni- 
versity of Michigan, 1894-99 ; Professor 
of Biology, Vassar College, 1899-; Member 
American Society of Morphologists; Mem- 
ber Michigan Academy of Sciences. 

Author of : — 

Preliminary Account of the Embryology 
of Unio complanata. Jour, of Morph., 
Aug., 1893, Vol. 8, pp. 569-578, 1 plate. 

The Embryology of the Unionidfe, a Study 
in Cell-Lineage. Ibid., Jan., 1895 ; Vol. 
10, pp. 1-100, 6 plates. 

On the Smallest Parts of Stentor Capable 
of Regeneration. A Contribution on 



Published Papers. 



511 



the Limit of Divisitiility of Living Mat- 
ter. Ibict. , May, 1896, Vol. 12, pp. 239- 
249. 

On the Effect of Temperature on the De- 
velopment of Animals?. (With F. P. 
Knowlton.) Zoological Bulletin, Dec. , 
1897, Vol. 1, pp. 179-193. 

On the Origin of the Centres of the First 
Cleavage Spindle in Unio complanata. 
Science, March 5, 1897, N. S., Vol. 5, 
pp. 389-390. 

Centrosome and Sphere in the Egg of Unio. 
Zoological Bxdletin, May, 1898, Vol. 1, 
pp. 265-274. 

Hertwig's "Zelle und Gewehe," Vol. 2. 
Science, Oct. 14, 1898, N. S.,Vol. 8, pp. 
617-520. 

Adaptation in Cleavage. Woods Holl 
Biological Lectures, 1898. Ginn & Co., 
Boston. (In press.) 

ERNEST H. LINDLET: — 

A. B., Indiana University, 1893; A.M..,ihid., 
1894 ; Instructor in Philosophy, iWc?., 1893- 
95 ; Fellovir in Psychology, Clark 
University, 1895-97; Ph.D., Clark 
University, 1897 ; Universities of Jena, 
Leipzig, and Heidelherg, 1897-98 ; Asso- 
ciate Professor of Psychology, Indiana 
University, 1898- ; Member American 
Psychological Association. 

Author of : — ^ 

A Preliminary Study of Some of the Mo- 
tor Phenomena of Mental Effort. Am. 
Jour, of Psy., July, 1896, Vol. 7, pp. 
491-517. 

Some Mental Automatisms. (With G. E. 
Partridge. ) Pedagogical Seminary, 
July, 1897, Vol. 5, pp. 41-60. 

A Study of Puzzles with Special Reference 
to the Psychology of Mental Adapta- 
tion. Am. Jour, of Psy., July, 1897, 
Vol. 8, pp. 431-493. 

Ueber Arbeit und Ruhe. Psychologische 
Arbeiten, herausg. von E. Kraepelin. 
Heidelberg. (In press.) 

C. E. LINEBARGER: — 

A.B. , Northwestern University, 1888 ; 
Student, Chicago Medical College, 1888- 



89 ; Student, Universities of Tiibingen and 
Paris, 1889-91 ; Fellow in Chemistry, 
Clark University, 1891 ; Instructor in 
Chemistry, North Division High School, 
Chicago, 1891-93 ; Student, University of 
Gottingen, 1893-94; Student, School of 
Mines, Paris, 1894 ; Instructor in Chem- 
istry and Physics, South Division High 
School, Chicago, 1894-96 ; Instructor in 
Chemistry and Physics, Lake View High 
School, Chicago, 1896-99; Member of: 
American Chemical Society, Chemical 
Society of Paris, German Electro- 
chemical Society. 

Author of: — 

An Examination of Fusel Oil. (With 
J. H. Long.) Jour, of Anal. Chem., 
1890, Vol. 4, p. 5. 

Sur I'Hydroxanthranol. Bull. d. I. Soc. 
Chimique, 1891, Vol. 6, p. 92. 

The Action of Benzene on Benzal Chloride 
In the Presence of Aluminium Chloride. 
Am. Chem. Jour., 1891,Vol. 13, p. 556. 

The Reaction between Triphenylmethane 
and Chloroform in the Presence of 
Aluminium Chloride. Ibid., p. 553. 

On Disulphotetraphenylene. Jour. Am. 
Chem. Soc, Vol. 13, p. 270. 

A Rapid Dialyzer. Jour, of Anal. Chem., 
1892, Vol. 6, p. 91. 

On the Nature of Colloid Solutions. Am. 
Jour, of Sci., 1892, Vol. 43, p. 218. 

The Molecular Masses of Dextrine and 
Gum Arabic as determined by their 
Osmotic Pressures. Ibid., p. 428. 

On the Formation of Layers in Solutions 
of Salts in Mixtures of Water and 
Organic Liquids. Am. Chem. Jour., 
1892, Vol. 14, p. 380. 

On the Relations between the Surface 
Tensions of Liquids and their Chemi- 
cal Constitution. Am. Jour, of Sci., 
1892, Vol. 44, p. 83. 

On the IniSuence of the Concentration of 
the Ions on the Intensity of Color of 
Solutions of Salts in Water. Ibid., p. 
416. 

The Dissociation of Salts into their Ions 
by Water of Crystallization. Am. 
Chem. Jour., 1892, Vol. 14, p. 604. 



512 



Titles of 



On the Application of the Friedel-Craffts 
Keaction to Syntheses in the Anthra- 
cene Series. Ibid., p. 602. 

On the Preparation and Constitution of 
Paraanthraoene. Ibid., p. 597. 

A Definition of Solutions. Science, 1892, 
Vol. 20, p. 352. 

The Solubility of Ti'iphenylmethane in 
Benzene. Am. Chem. Jour., 1893, 
Vol. 15, p. 45. 

The Hydrates of Manganous Sulphate. 
Ibid., 1893, Vol. 15, p. 225. 

On the Existence of Double Salts in Solu- 
tion. Ibid., 1893, Vol. 15, p. 387. 

An Isothermal Curve of Solubility of 
Mercuric and Sodium Chlorides in 
Acetic Ether. Ibid., 1894, Vol. 16, 
p. 215. 

The Benzoyl Halogen Amides. Ibid., 
1894, Vol. 16, p. 218. 

Ueber die Bestimmung kleiner Dissocia- 
tionsspannungen speciell Krystallwas- 
serhaltiger Salze. Zeits. f. phys. 
Chemie, 1894, Vol. 13, p. 500. 

Some Modifications of Beckmann's Ebul- 
liosoopic Apparatus. Chemical News, 
1894, Vol. 69, p. 279. 

The Boiling Points of Dilute Solutions of 
Water in Alcohol and in Ether. Ibid. , 
p. 613. 

On the Application of the Schroeder-Le- 
Chatelier Law of Solubility to Solutions 
of Salts in Organic Liquids. Am. 
Jour, of Sci., 1895, Vol. 49, p. 48. 

The Combination of Sulphur with Iodine. 
Am. Chem. Jour., 1895, Vol. 17, p. 
33. 

On Some Experiments in the Anthracene 
Series. Joui: Am. Chem. Soc, 1895, 
Vol. 17, p. 351. 

On the .Reaction between Zinc Sulphate 
and Potassium Hydroxide. Ibid., p. 
358. 

On Some Relations between Temperature, 
Pressure, and Latent Heat of Vapor- 
ization. Am. Jour, of Sci., 1895, Vol. 
49, p. 380. 

On the Vapor Tensions of Mixtures of 
Volatile Liquids. Jour. Am. Chem. 
Sac, 1895, Vol. 17, p. 580. 

On the Formation of Layers in Mixtures 



of Acetic Acid and Benzene. Ibid.,^). 
932. 

On the Heat ESect of mixing Liquids. 
Physical Review, 1896, Vol. 3, p. 418. 

On the Specific Gravities of Mixtures of 
Normal Liquids. Am. Chem. Jour., 
1896, Vol. 18, p. 428. 

A Rapid Method of determining the Mo- 
lecular Masses of Liquids by Means of 
their Surface Tensions. Jour. Am. 
Chem. Soc, 1896, Vol. 18, p. 514. 

On the Reaction between Carbon Tetra- 
chloride and the Oxides of Niobium 
and Tantalum. (In collaboration with 
M. Delafontaine.) Ibid., p. 32. 

Ueber die Dielektricitatskonstanten von 
Flussigkeitsgemischen. Zeitschr. f. 
phys. Chemie, 1896, Vol. 20, p. 131. 

An Apparatus for the Rapid Determina- 
tion of the Surface Tensions of Liquids. 
Am. Jour. Set, 1896, Vol. 2, p. 108. 

On the Surface Tension of Mixtures of 
Normal Liquids. Ibid., p. 226. 

On the Viscosity of Mixtures of Liquids. 
Ibid., p. 331. 

The Phase Rule. By Wilder D. Bancroft. 
Review. Monist, 1897, Vol. 7, p. 634. 

Grundziige einer thermodynamischen 
Theorie elektrochemischer Krafte. By 
Alfred H. Bucherer. Review. Ibid., 
p. 635. 

The Phase Rule. By Wilder D. Bancroft. 
Review. Jour. Am. Chem. Soc, 1897, 
Vol. 19, p. 767. 

The Surface Tensions of Aqueous Solu- 
tions of Oxalic, Tartaric, and Citric 
Acids. Ibid., 1898, Vol. 20, p. 128. 

An Outline of the Theory of Solution and 
its Results. By J. Livingston R. Mor- 
gan. Review. iSid., 1898,Vol. 20,p. 
153. 

The Principles of Mathematical Chemis- 
try. By J. Livingston R. Morgan. 
Review. Ibid., 1898, Vol. 20, p. 155. 

On the Speed of Coagulation of Colloid 
Solutions. Ibid., 1898, Vol. 20, p. 
375. 

Text-book of Physical Chemistry. By 
Clarence L. Speyers. Review. Ibid., 
1898, Vol. 20, p. 389. 

On a Balance for Use in Courses in Ele- 



Published Papers. 



513 



mentary Chemistry. Ibid. , 1899, Vol. 

21, p. 31. 
The Surface Tension of Aqueous Solutions 

of Alkaline Chlorides. lUd., 1899, 

Vol. 21, p. 327. 
A Simple Voluminometer. Ibid., 1899, 

Vol. 21, p. 435. 
The Elements of Differential and Integral 

Calculus. (In collaboration with J. W. 

A. Young.) 1899, D. Appleton & Co. 

SIDNEY J. LOCHNER : — 

A.B., Union College, 1890; A.M.., ibid., 
1892 ; First Assistant in Astronomy, Dud- 
ley Observatory, Albany, N. Y., 1889-92 ; 
PelloTv in Physics, Clark University, 
Oct., 1892-May, 1893 ; Assistant, Har- 
vard Observatory, 1893 ; Admitted as At- 
torney at Law, Detroit, Mich., Dec, 
1893; Professor of Physics and Mathe- 
matics, Delaware Literary Institute, 
Franklin, N. Y., 1894-. 

Author ol: — 

On the Elongation Produced in Soft Iron 
by Magnetism. Phil. Magazine, Dec, 
1893, Fifth Series, Vol. 36, pp. 498- 
507. 

Modem Scientific Investigations. Union 
College Concordensis, 1894. 

WILLIAM E. LOCKWOOD : — 

Ph.B., Sheffield Scientific School, Yale 
University, 1883; M.D., i6i(i., 1885 ; in- 
structor in Chemistry, ibid., 1885-86 ; In- 
structor and Demonstrator in Physiology, 
ibid., 1887-91 ; Fellow in Physiology, 
Clark University, 1891-92. 
Died at Kedlands, Cal., June 23, 1897. 

Author of : — 

The New Haven Water Supply : A Criti- 
cism of the Kesults of Analyses of 
this "Water, as given by Dr. Arthur J. 
Wolff, in the Report of the Connecticut 
State Board of Health for 1885. (With 
Herbert E. Smith, M.D.) New Haven. 
6 pp. 

Report of the Analyses of One Hundred 
and Ten Well Waters, collected in 
New Haven. (With Herbert E. Smith, 
M.D.) Report of the Connecticut 



State Board of Health, 1886, pp. 259- 
269. 
Some Hints for the Physician concerning 
Urinary Analysis. Medical Register, 
Philadelphia, March 19, 1887, Vol. 1, 
pp. 169-174. 

MORRIS LOEB : — 

A.B., Harvard University, 1883; Ph.D., 
University of Berlin, 1887 ; Assistant to 
Professor Wolcott Gibbs, 1888-89 ; Do- 
cent in Physical Chemistry, Clark 
University, 1889-91 ; Professor of 
Chemistry, New York University, N. Y. 
City, 1891-. 

Author of : — 

Ueber die Einwirkung von Phosgen auf 
Aethenyldiphenyldiamin. Ber. d. 
deut. chem. Gesellschaft, Aug., 1885, 
Vol. 18, pp. 2427-2428. 

Ueber Amidinderi vate. Ibid. , Aug. , 1886, 
Vol. 19, pp. 2340-2444. 

Das Phosgen und seine Abkbmmlinge. 
Berlin, March 15, 1887. 61 pp. 

The Molecular Weight of Iodine in its 
Solutions. Jour, of Chem. Soc, 
Trans., 1888, Vol. 53, pp. 805-812. 
Also Zeits. f. physikalische Chemie, 
July, 1888, Vol. 2, pp. 606-612. 

The Use of Aniline for Absorbing Cyano- 
gen in Gas Analysis. Jour, of Chem. 
Soc, Trans., 1888, Vol. 53, pp. 812- 
814. 

The Rates of Transference and the Con- 
ducting Power of Certain Silver Salts. 
(With W. Nernst.) Am. Chem. Jour., 
Feb., 1889, Vol. 11, pp. 106-121. Also 
Zeits. f. physikalische Chemie, Nov., 
1888, Vol. 2, pp. 948-963. 

Is Chemical Action Afiected by Magnet- 
ism? Am. Chem. Jour., March, 1891, 
Vol. 13, pp. 145-153. 

WARREN P. LOMBARD: — 

A.B., Harvard University, 1878; M.D., 
Harvard Medical School, 1881 ; University 
of Leipzig, 1882-85; Assistant in Physi- 
ology, College of Physicians and Surgeons, 
New York City, 1888-89 ; Assistant Pro- 
fessor of Physiology, Clark Univer- 



514 



Titles of 



sity, 1889-92 ; Professor of Physiology, 
University of IVIichigan, 1892- ; Member 
American Physiological Society. 

Author of : — 

Beitrage zux Theorie der Warmeempfin- 
dung. Vorlaufige Mitteilimg. Cen- 
tralU. f. d. Med. Wissensck., 1883, 
Vol. 21, pp. 577-579. 

Die raumliche und zeitliche Aufeinander- 
folge refleotorisch contrahirter Mus- 
keln. Arch. f. Anat. u. Physiologie 
Physiol. Abthl., 1885, pp. 408-489. 

Is the "Knee-jerk" a Reflex Act? Am. 
Jour, of Med. Sciences, Jan., 1887. 

The Variations of the Normal " Knee' 
jerk." Am. Jour, of Psy., Nov., 1887 
Vol. 1, pp. 5-71. 

Die Variationen des normalen Kniestosses, 
Arch. f. Anat. u. Physiologie, SuppI 
Band, 1889, pp. 292-335, 10 pis. 

On the Nature of the " Knee-jerk." Jour, 
of Physiology, Feb., 1889, Vol. 10, pp 
122-148. 

The Effect of Patigue on Voluntary Mus- 
cular Contraction. Am. Jour, of Psy., 
Jan., 1890, Vol. 3, pp. 24-42. 

Effet de la fatigue sur la contraction mus- 
culaire volontaire. Arch. Ital. de Biol- 
ogie, 1890, Vol. 13, pp. 371-381. 

Alterations in the Strength vphich occur 
during Fatiguing Voluntary Muscular 
Work. Jour, of Physiology, Jan., 
1893, Vol. 14, pp. 97-124. 

General Physiology of Muscle and Nerve. 
Chapter II., Howell's Am. Text Book 
of Physiology. W. B. Saunders, Phila- 
delphia, 1896. pp. 32-151. 

FRANK H. LOUD : — 

A.B., Amherst College, 1873 ; Walker In- 
structor in Mathematics, ibid., 1873-76; 
Professor of Mathematics, Colorado Col- 
lege, 1877- ; Director of State Weather 
Service, Colorado, 1889-90; Scholar 
in Mathematics, Clark University, 
1890-91. 

Author of : — 

A Rigorous Elementary Proof of the 
Binominal Theorem. Col. College 
Studies, 1890, pp. 7-15. 



On Certain Cubic Curves. Ibid., 1890, p. 
16. 

The Elliptic Functions Defined Indepen- 
dently of the Calculus. Ibid., 1891, 
pp. 48-81. 

EL"WYN N. LOVEWELL : — 

Ph.B., University of Vermont, 1898 
(Double Honors) ; Scholar in Mathe- 
matics, Clark University, 1898-99. 

GEORGE "W. A. LUCKEY: — 

Teacher in Public Schools of Indiana, 
1874-78 ; Superintendent of Schools, 
Adams Co., Ind., 1878-82 ; Superinten- 
dent of Schools, Decatur, Ind., 1882- 
87 ; Supervising Principal, Ontario, Cal., 
1888-92 ; Non-Resident Student, Univer- 
sity of City of New York, 1889-92 ; Stu- 
dent in Pedagogy and Psychology, Leland 
Stanford Jr. University, 1892-94 ; A.B., 
ibid., 1894; Fellow in Psychology, 
Clark University, 1894-95 ; Associate 
Professor of Pedagogy, University of Ne- 
braska, 1895-96 ; Professor of Pedagogy, 
ibid., 1896- ; Editor of the Child Study 
Department, Northwestern Monthly, 1895- 
99. 

Author of : — 

Comparative Observations on the Indirect 
Color Range of Children, Adults, and 
Adults Trained in Color. Am. Jour, 
of Psy., Jan., 1895, Vol. 6, pp. 489- 
504. 

Some Recent Studies of Pain. Ibid., Oct. , 

1895, Vol. 7, pp. 108-123. 

Child Study in its Effects upon the 
Teacher. Child Study Monthly, Feb., 

1896, Vol. 1, pp. 230-247. 
Children's Interests. Northw. Monthly, 

1896-97, Vol. 7, pp. 67, 96, 133, 156, 

221, 245, .306, and 335. 
Practical Results Obtained through the 

Study of Children's Interests. Proc. 

N. E. A., 1897, pp. 284-288 ; also Jour. 

of Ed., Apr. 8, 1897, Vol. 45, p. 222. 
Lines of Child Study for the Teacher. 

Educational Seview, Nov., 1897, Vol. 

14, pp. 340-347 ; also Proc. N. E. A., 

1897, pp. 826-833. 



Published Papers. 



515 



A Brief Survey of Child Study. NoHh- 

western Jour, of Ed., July, 1896, Vol. 

7, pp. 2-9. 
Methods Pursued in Child Study. ' Ibid., 

pp. 33-35. 
The Best "Works on Child Study. Ibid., 

pp. 48-53. 
The Development of Moral Character. 

Proc. N. E. A., 1899. 

HERMAN T. LUKENS : — 

A.B., University of Pennsylvania, 1885; 
A.M., ibid., 1888 ; Student in Halle, Jena, 
and Berlin, 1888-91 ; Ph.D., University of 
Jena, 1891 ; Instructor in Biology, N. W. 
Division High School, Chicago, 1891-94 ; 
Honorary Fellow in Psychology, 
Clark University, 1894-95 ; Decent 
in Pedagogy, 1895- ; Lecturer in 
Education, Bryn Mawr College, 1896-97 ; 
Visit to Europe to study Education, 
1897-98 ; Head Training Teacher, S. "W. 
State Normal School, California, Pa., 
1898-. 

Author of : — 

Herbart's Psychological Basis of Teach- 
ing. Part II of Th. B. Noss's Outlines 
of Psychology and Pedagogy, Pitts- 
bui-g, 1890. 

Die Vorstellungsreihen und Dire padago- 
gische Bedeutung. Giltersloh, Prussia, 
1892. 

A Portion of the Translation of Lange's 
Apperception. Edited by Charles De 
Garmo. D. C. Heath & Co., Boston, 
1893. 279 pp. 

The Connection between Thought and 
Memory. Based on Dorpfeld's Den- 
ken und Gedachtnis. D. C. Heath & 
Co., Boston, 1895. 179 pp. 

The Correlation of Studies. Educational 
Review, Nov., 1895, Vol. 10, pp. 364- 
383. 

Correlation. Jour, of Ed., May 9 and 
June 20, 1895, Vol. 41, pp. 311-312 ; 
Vol. 42, p. 15. 

A Point of Difference between Race and 
Individual Development. Second Her- 
bartian Yearbook, 1896. 

Preliminary Report on the Learning of 



Language. Pedagogical Seminary, 
June, 1896, Vol. 3, pp. 424-460. 
A Study of Children's Drawings in the 
Early Years. Ibid., Oct. 1896, Vol. 
4, pp. 79-110. 
Child Study for Superintendents. Edu^ 
cational Seview, Feb., 1897, Vol. 13, 
pp. 105-120. 
Honorary Degrees in the United States. 
Ibid., June, 1897, Vol. 14, pp. 8-16. 
Language Defects. Northw. Monthly, 

July, 1897, Vol. 8, pp. 39-44. 
The Vital Question in the Curriculum. 
Education, Sept., 1897, Vol. 18, pp. 
19-29. 
Die Entwiokelungsstufen beim Zeichnen. 
Kinderfehler, Dec, 1897, Vol. 2, pp. 
166-170. 
Malendes Zeichnen. Aus dem pad. 

Univ.- Seminar Jena, VII., 1897. 
The School Fatigue Question in Ger- 
many. Educational Eevieio, March, 
1898, Vol. 15, pp. 246-254. 
The Method of Suggestion in the Cure of 
Faults. Northwestern Monthly, May, 
1898, Vol. 8, pp. 592-595. 
The School and Real Lite. iV. Y. School 
Jour., Oct. 1, 1898, Vol. 57, pp. 277- 
279. 
Notes Abroad. Pedagogical Seminary, 

Oct., 1898, Vol. 6, pp. 114-125. 
A School-Garden in Thuringia. Educa- 
tional Beview, March, 1899, Vol. 17, 
pp. 237-241. 
Mental Fatigue. Am. Phys. Ed. Beview. 
March and June, 1899, Vol. 4, pp, 
19-29, 121-135. 
The Joseph Story. IST. Y. Teachers' 
Magazine, April, 1899, Vol. 1, pp, 
331-334. 
Drawing in the Early Years. Proc. N. 
E. A., 1899. 

ALEXANDER G. McADIE: — 

A.B., College of City of New York, 1881 ; 
A.M., ibid., 1884 ; Student, Harvard Uni- 
versity, 1882-85 ; A.M., ibid., 1885; Phys- 
ical Laboratory, U. S. Signal Of&ce, 1886- 
87 ; Fellow in Physics, Clark Univer- 
sity, 1889-90; U. S. Signal Office, 
Washington, 1890-91 ; U. S. "Weather Bu- 



516 



Titles of 



reau, Washington, 1891-95; Hodgkins 
Medal and Honorable Mention, Smith- 
sonian Institution, 1895; Local Forecast 
Official, New Orleans, 1898-99; Forecast 
Official, San Francisco, 1899-; Honorary 
Lecturer in Meteorology, University of 
California; Director, California Climate 
and Crop Service. 

Author of: — 

On the Aurora. U. 8. Signal Service 
Note, No. 18, pp. 21, 5 maps, 12 charts. 

Protection against Lightning. Am. Met. 
Jour., June, 1885, Vol. 2, pp. 60-66. 

Atmospheric Electricity at High Altitudes. 
Proc. Am. Academy, 1885, Vol. 13, pp. 
129-134. 

Electrometer Work. Monthly Weather 
Beview, 1886-87, Vol. 14, pp. 166-167. 

Observations of Atmospheric Electricity. 
Am. Met. Jour., March, 1887, Vol. 3, 
pp. 523-531 ; April, 1887, Vol. 3, pp. 
551-561 ; May, 1887, Vol. 4, pp. 21-31. 

William Terrell. Ibid., Feb., 1888, Vol. 
4, pp. 441-449. 

Lightning and the Electricity of the At- 
mosphere. Ibid., May, 1889, Vol. 6, 
pp. 1-4. 

Tornadoes. Prize Essay. Ibid., Vol. 7, 
pp. 179-192. 

Mean Temperatures in the United States. 
Professional Paper, U. S. Signal Office, 
June, 1891. Washington, 1891. 45 pp. 

Franklin's Kite Experiment. Am. Met. 
Jour., July, 1891, Vol. 8, pp. 97-108. 

Shall We erect Lightning Rods? Ibid., 
July, 1892, Vol. 9, pp. 60-66. 

Experiments in Atmospheric Electricity. 
Annals of Observatory of Harvard Col- 
lege, Vol. 40, Part 1, pp. 53-58. 

Experiments in Atmospheric Electricity at 
Blue Hill, 1892. Annals of Observa- 
tory of Harvard College, Vol. 40, Part 
2, pp. 120-124. 

Energy of a Flash of Lightning. Proc. of 
the Internat. Met. Congress, Chicago, 
1893, Paper 5, Part 1, pp. 18-21. 

Utilization of Cloud Observations. Ibid., 
Paper 6, Part 1, pp. 21-26. 

Protection from Lightning. U. S. Weather 
Bureau, Bulletin No. 15, 1894. 



A Colonial Weather Service. Pop. Sci. 
Mo., July, 1894, Vol. 45, pp. 331-337. 

The Storage Battery of the Air. Harper's 
Magazine, July, 1894, Vol. 89, pp. 216- 
219. 

New Cloud Classifications. Pi-oc. Phil. 
Soc. of Washington, March 2, 1895, 
Vol. 13, pp. 77-86. 

The Work and Equipment of an Aero- 
Physical Laboratory. Smithsonian In- 
stitution, 1895. 30 pp. Smithsonian 
Miscellaneous Collections, Vol. 39, No. 
1077. 

Fog Possibilities. Harper's Magazine, 
Jan., 1897, Vol. 94, pp. 263-266. 

What is an Aurora ? Century Magazine, 
Oct., 1897, Vol. 54, pp. 874-878. 

Franklin's Kite Experiments. Pop. Sci. 
Mo., Oct. 1897, Vol. 51, pp. 739-747. 

Needless Alarm during Thunder-storms. 
Century Magazine, Aug., 1899, Vol. 58, 
pp. 604-605. 

FRANK H. MoASSEY: — 

A.B., Ripon College, Ripon, Wis., 1897; 
Scholar in Psychology, Clark Univer- 
Bity, 1898-99. 

J. F. Mcculloch : — 

A.B., Adrian College, 1883 ; A.M., ibid., 
1889; Ph.B., i6M., 1884; Assistant Pro- 
fessor of Mathematics, ibid., 1885-87 ; In- 
structor in Mathematics, University of 
Michigan, 1887-88 ; Assistant Professor 
of Mathematics, Adrian College, 1888-89 ; 
Fellow in Mathematics, Clark Univer- 
sity, 1889-90; President, Adrian Col- 
lege, 1890-93 ; Pastor of M. P. Church, 
Fairmont, W. Va., 1893-94; Editor, Our 
Church Record, Greensboro, N. C, 1894r-. 

Author of : — 

RoUe's Theorem extended. Annals of 

Mathematics, Vol. 4, p. 5. 
A Theorem in Factorials. Ibid., Vol. 4, 

p. 161. 

ARTHUR MacDONALD: — 

A.B., University of Rochester, 1879 ; A.M., 
ibid., 1883; Union Theological Seminary, 
1880-83 ; Graduate Student, Harvard Uni- 
versity, 1883-85; FeUow, Johns Hopkins 



Published Papers. 



517 



University, 1885; Universities of Berlin, 
Leipzig, Paris, and Ziirich, 1885-88 ; Do- 
cent in Ethics, Clark University, 1889- 

91 ; Specialist in Education as related to 
the Abnormal and Weakling Classes, U. S. 
Bureau of Education, 1891- ; U. S. Dele- 
gate, International Criminal Congress, 
Brussels, 1892 ; International Psychological 
Congress, London, 1893 ; International De- 
mographioal Congress, Budapest, 1894. 

Author of: — 

Ethics as Applied to Criminology. Jour, 
of Mental Science, Jan., 1891, Vol. 37, 
pp. 10-16, and Open Court, July, 1891. 

Alcoholism. Medico-Legal Journal, June, 
1891. 

Criminal Aristocracy, or the Maffia. Med- 
ico-Legal Journal, June, 1891, Vol. 9, 
pp. 21-26. 

Criminology. With an Introduction by C. 
Lombroso, with Bibliography. Funk & 
Wagnalls Co. , New York, 1894. 416 pp. 

Abnormal Man. Being Essays on Eduoa- 
cation and Crime and Related Subjects, 
with Digests of Literature and a Bibli- 
ography. U. S. Bureau of Education, 
Washington, 1893. 445 pp. 

Le Criminel-Type dans quelques formes 
graves de la Criminality. Bibliographic 
de Sexualitfe Pathologique. Un volume 
in 8° illustr6 de Portraits. A Storck, 
Lyon et G. Masson, Paris, 1895. 300 pp. 

Education and Patho-Social Studies. Re- 
print from Annual Beport of U. S. 
Commissioner of Education for 1893- 
94, Washington, D. C, 1896. 57 pp. 

'kmile Zola : a Psycho-Physical Study of 
Zola's Personality. Reprint from Open 
Court, August, 1898. 18 pp. 

Experimental Study of Children, including 
Anthropometrical and Psycho-Physical 
Measurements, with a Bibliography. 
Reprint from Annual Beport of U- S. 
Commissioner of Education for 1897- 
98, Washington, D. C, 1899. 325 pp. 

Ueber Korpermessungen an Kindern. 
Deuts. Zeits. f Ausldndisches TJnter- 
richtsioesen, July, 1899, Vol. 4, pp. 
25.S-266. 
Abnormal Children. (In press.) 



JOHN McGOWAN: — 

B. A., University of Toronto, 1888 ; Fellow 
in Mathematics, ibid. , 1888-91 ; Scholar 
in Mathematics, Clark University, 
1891-92 ; Instructor in Mathematics, 
Princeton College, 1892-93; Graduate 
Student, University of Toronto, 1893-94 ; 
Lecturer in Mathematics and Physics, 
Toronto Technical School, 1894-95 ; B.S., 
University of Toronto (School of Practical 
Science), 1895. 

J. PLAYPAIR McMUHRICH : — 

B. A., University of Toronto, 1879 ; M.A., 
ibid., 1882 ; Assistant in Biological Lab- 
oratory, ibid., 1880-81 ; Professor of Biol- 
ogy, Ontario Agricultural College, 1882-84 ; 
Instructor in Osteology, Johns Hopkins 
University, 1884-86; Ph.D., Johns Hop- 
kins University, 1885 ; Professor of Biology, 
Haverford College, 1886-89; Docent in 
Morphology, Clark University, 1889- 
91 ; Assistant Professor, 1891-92 ; 
Professor of Biology, University of Cin- 
cinnati, 1892-94 ; Professor of Anatomy, 
University of Michigan, 1894r-. 

Author of : — 

On the Origin of the So-called TesUcells in 
the Ascidian Oviun. Studies from 
Biol. Lab. J. H. U. , 1882, Vol. 2. Ab- 
stract in Biol.Centralblatt, 1882, Vol. 2; 
Arch. deZool. exp. etgen., 1882, Vol. 10. 

Note on the Function of the " Test-cells " 
in Ascidian Ova. Zool. Ameiger, 1882, 
Vol. 5. Abstract in Jour. Boy. Micros. 
Soc, 1882, Vol. 2. 

On the Osteology and Development of 
Syngnathus peckianus (Storer). 
Quart. Jour. Micros. Sci., 1883, Vol. 
23. Abstract in J. H. U. Circular, 

1883, No. 27. 

The Osteology and Myology of Amiurus 
catus (L.) Gill. Proc. of the Canadian 
Inst., Toronto, 1884, Vol. 2. Pre- 
liminary Notice in Zool. Anzeiger, 

1884, Vol. 7. 

On the Structure and AfiSnities of Phytop- 
tus. J. H. U. Circular, 1884, No. 35. 
Abstract in Jour. Boy. Micros. Soc, 

1885, Vol. 5. 



518 



Titles of 



On the Tape-worm Epizootic among 
Lambs (Taenia expansa). 9th Ann. 
Rep. of the Ont. Agricultural College, 
Toronto, 1884. 

The Cranial Muscles of Amia calva (L.), 
■with a consideration of the Post-occipi- 
tal and Hypoglossal Nerves in the 
various Vertebrate Groups. Studies 
from Biol. Lab. J. H. U., 1885, Vol. 3. 
Preliminary Notice in J. H. U. Circu- 
lar, 1885, No. 38. 

On the Existence of a Post-oral Band of 
Cilia in Gasteropod Veligers. J. H. U. 
Circular, 1885, No. 43. Abstract in 
Jour. Boy. Micros. Soc, 1886, Vol. 
6. 

A Contribution to the Embryology of 
the Prosobranch Gasteropods. Studies 
from Biol. Lab. J. H. U., 1886, Vol. 3. 
Preliminary Notice in J. H. U. Circular, 
1886, No. 49. Abstract iu Jour. Boy. 
Micros. Soc, 1886, Vol. 6. 

Notes on the Actiniae obtained at Beau- 
fort, N. C. Studies from Biol. Lab. 
J. H. U., 1887, Vol. 4. 

On the Occurrence of an Edwardsia Stage 
in the Free-swimming Embryos of a 
Hexactinian. J. H. U. Circular, 
1899, No. 70. Abstract in Jour. Boy. 
Micros. Soc, 1889, Vol. 9. 

A Contribution to the Actinology of the 
Bermudas. Proc of the Acad, of Nat. 
Sciences, Philadelphia, 1889. Abstract 
in Jour. Boy. Micros. Soc, 1889, Vol. 
9. 

Note on the Structure and Systematic 
Position of Lebrunea neglecta, Duoh. 
and Mich. Zool. Anzeiger, 1880, Vol. 
12. Abstract in Jour. Boy. Micros. 
Soc, 1889, Vol. 9. 

Article " Reproduction " in Buck's Befer- 
ence Handbook of the Medical Sciences, 

1889, Vol. 8. 

The Actiniaria of the Bahama Islands, 
W. I. Jour, of Morph., 1889, Vol. 3. 
Abstract in Jour. Boy. Micros. Soc, 

1890, Vol. 10 ; American Naturalist, 
1889 ; Preliminary Notice in J. H. XJ. 
Circular, 1889, No. 70. 

Contributions on the Morphology of the 
Actinozoa. I. The Structure of Ceri- 



anthus americaniis. Jour, of Morph., 
Oct., 1890, Vol. 4, pp. 131-150. 

Contributions on the Morphology of the 
Actinozoa. II. On the Development 
of the Hexactinice. Ibid., Jan., 1891, 
Vol. 4, pp. 303-330. 

Contributions on the Morphology of the 
Actinozoa. III. The Phylogeny of the 
Actinozoa. Ibid., June, 1891, Vol. 5, 
pp. 125-164. 

The Gastrsea Theory and its Successors. 
Biological Lectures, Marine Biological 
Laboratory, Woods HoU. Ginn & Co., 
Boston, 1891, pp. 79-106. 

The Formation of the Germ-layers in the 
Isopod Crustacea. Zool. Anzeiger, 
Jahrg. 15, 1892. 

Eeport on the Actinise collected by the U. 
S. Fish Commission steamer Albatross 
during the winter of 1887-88. Proc. 
U. S. National Museum, 1893, Vol. 16, 
p. 119. 

A Text-book of Invertebrate Morphology. 
New York, 1894. 

Embryology of the Isopod Crustacea. 
Jour, of Morph., May, 1895, Vol. 11, 
pp. 63-154. 

Cell Division and Development. Biologi- 
cal Lectures, Marine Biological Labora^ 
tory. Woods Holl. Ginn & Co. , Boston, 
1895, pp. 125-147. 

Notes on Some Actinians from the Ba- 
hama Islands, collected by the late Dr. 
J. I. Northrop. Annals N. T. Acad, 
of Science, 1896, Vol. 9, p. 181. 

The Yolk-lobe and Centrosome of Fulgur 
carica. Anat. Anzeiger, 1896, Bd. 12, 
p. 534. 

Contributions on the Morphology of the 
Actinozoa. IV. On Some Irregulari- 
ties in the Number of the Directive 
Mesenteries in the Hexaotinise. Zool. 
Bulletin, 1897, Vol. 1. 

The Epithelium of the So-called Midgut 
of the Terrestrial Isopods. Joiir. of 
Morph., 1897, Vol. 14, p. 83. 

A Case of Crossed Dystopia of the Kid- 
ney with Fusion. Jour, of Anat. and 
Phys., 1898, Vol. 32, p. 652. 

Report on the Actiniaria collected by the 
Bahama Expedition of the State Uni- 



Published Papers. 



519 



yersity of Iowa, 1893. Bull. Lab. of 
Nat. Hist. State Univ. of Iowa, 1898, 
Vol. 4, p. 225. 
The Present Status of Anatomy. Amer- 
ican Naturalist, 1899, Vol. 33, p. 185. 

FRANKLIN P. MALL: — 

M.D., University of Michigan, 1883; 
University of Heidelberg, 1883-84; 
University of Leipzig, 1884-86 ; Fellow, 
Instructor, and Associate in Pathology, 
Johns Hopkins University, 1886-89 ; Ad- 
junct Professor of Vertebrate Anat- 
omy, Clark University, 1889-92 ; Pro- 
fessor of Anatomy, University of Chicago, 
1892-93 ; Professor of Anatomy, Johns 
Hopkins University, 1893-. 

Author of : — 

Entwiokelung der Branchialbogen und 

-Spalten des Hiihnchens. Arch. f. 

Anatomie (His u. Braune), 1887, 

pp. 1-34, 3 pis. 
Die Blut- und Lymphwege im Diinndarm 

des Hundes. Abhandl. d. K. 8. Ge- 

sellsch. der Wissenschaften, 1887, Vol. 

24, pp. 153-189, 6 pis. 
The First Branchial Arch of the Chick. 

J. H. U. Circular, Feb., 1888, Vol. 

7, p. 38. 
The Branchial Region of the Dog, Ibid., 

Feb., 1888, Vol. 7, p. 39. 
Development of the Eustachian Tube, 

Middle Ear, Tympanic Membrane, and 

Meatus of the Chick. Studies from 

Biol. Lab. J. H. U., June, 1888, Vol. 

4, pp. 185-192, 1 pi. 
The Development of the Branchial Clefts 

of the Dog with Special Reference to 

the Origin of the Thymus Gland. 

Ibid., pp. 193-216, 3 pis. 
Reticulated and Yellow Elastic Tissues. 

Anat. Anzeiger, June 1, 1888, Vol. 3, 

pp. 397-401. 
Die motorischen Nerven der Portalvene. 

Du Bois-Beymond's Arch.f. Physiolo- 

gie, 1890, Supp. Band, pp. 57-58. 
Development of the Lesser Peritoneal 

Cavity in Birds and Mammals. Jour. 

of Morph., June, 1881, Vol. 5, pp. 

165-179. 



Das Reticulirte Gewebe. Abhandl. d. K. 

S. Gesellsch. der Wissenschaften, 1891, 

Vol. 17, pp. 293-338, 11 pis. 
A Human Embryo Twenty-six Days Old. 

Jour, of Morph., Dec, 1891, Vol. 5, 

459-480, 2 pis. 
Methods of preserving Human Embryos. 

American Naturalist, Dec, 1891, Vol. 

25, pp. 1144-1146. 
Der Einfluss des Systems der Vena portae 

auf die Vertheilung des Blutes. Du 

Bois-Beymond' s Arch. f. Physiologie, 

1892, pp. 409-453. 

The Vessels and Walls of the Dog's Stom- 
ach. J. H. Hospital Beports, 1896, 
Vol. 1, pp. 1-36, 5 pis. 

A Study of the Intestinal Contraction. 
Ibid., pp. 37-75, 3 pis. 

Healing of Intestinal Sutures. Ibid., 
pp. 76-92. 

Reversal of the Intestine. Ibid., pp. 93- 
110. 

A Human Embryo of the Second Week. 
Anat. Anzeiger, Aug. 5, 1893, Vol. 8, 
pp. 630-633. 

Histogenesis of the Retina in Amblystoma 
and Necturus. Jour, of Morph. , May, 

1893, Vol. 8, pp. 415^32. 

Coelom, pp. 184-189 ; Human Embryos, 
pp. 268-269 ; The Heart, pp. 391-395 ; 
Development of the Thymus Gland, 
pp. 875-877 ; Development of the 
Thyroid Gland, pp. 879-882. Bef. 
Handbook of Med. Sciences (Supp. 
Vol.). 

What is Biology ? Chautauquan, Jan., 

1894, Vol. 18, pp. 411-414. 

Early Human Embryos and the Mode of 

their Preservation. Bull, of J. H. 

Hospital, Dec, 1893, Vol. 4, pp. 115- 

121. 
The Preservation of Anatomical Material 

for Dissection. Anat. Anzeiger, April 

9, 1896, Vol. 11, pp. 769-775. 
The Contraction of the Vena Portse and 

its Influence upon the Circulation. J. 

H Hospital Beports, 1896, Vol. 1, pp. 

111-156. 
Reticulated Tissue and its Relation to the 

Coimective Tissue Fibrils. Ibid., 1896, 

Vol. 1, pp. 171-208, 9 pis. 



520 



Titles of 



The Anatomical Course and Laboratory 

of the Johns Hopkins University. 

Bull, of J. B. Hospital, May^une, 

1896, Vol. 7, pp. 85-100, 5 pis. 
Development of the Human Ccelom. 

Jour, of Morph., Feb., 1897, Vol. 12, 

pp. 395-453. 
TJeher die Entwickelung des menschlichen 

Darmes und seiner Lage beim Ervfach- 

senen. His.'' s Arch. f. Anatomie, 1897, 

Supp. Band, pp. 403-434, 10 pis. 
Development of the Ventral Abdominal 

Walls in Man. Jour, of Morph. , June, 

1898, Vol. 14, pp. 347-366, 6 pis. 
Development of the Human Intestine and 

its Position in the Adult. B^tll. of 

J. H. Hospital, Sept. -Oct., 1898, Vol. 

9, pp. 197-208, 5 pis. 
The Lobule of the Spleen. Ihid., pp. 

218-219. 
Development of the Internal Mammary 

and Deep Epigastric Arteries in Man. 

lUd., pp. 2.32-235. 
The Value of Embryological Specimens. 

Md. Med. Jour., Oct. 29, 1898, Vol. 

40, p. 29. 
Liberty in Medical Education. Fhila. 

Med. Jour., AprU 1, 1899, Vol. 3, p. 

720. 

CHARLES VST. MARSH: — 

Ph.B., Columbia College, School of 
Mines, 1879; Ph.D., Columbia College, 
1882 ; Assistant in Chemistry, Green 
School of Science, Princeton, N. J., 1882- 
85; University of Berlin, 1885-87; Assist- 
ant in Chemistry, Lehigh University, 
1887-89 ; Honorary FeUow in Chemis- 
try, Clark University, 1889-90 ; Elec- 
trical Engineer, New York City, 1893-. 

Author of : — 

Note on the Ammonia-Process for Water 
Analysis. Am. Chem. Jour., July, 
1882, Vol. 4, pp. 188-192. 

A Method for the Detection of Chlorine, 
Bromine, Iodine, and Sulphur in Or- 
ganic Compounds. Ihid., April, 1889, 
Vol. 11, pp. 240-244. 

A New Form of Adapter. Am. Jour, of 
Anal. Chem., Jan., 1889. 



The Reduction of Barium Sulphate to 
Barium Sulphide on Ignition with 
Filter Paper. Z6tU, April, 1889. 

ALFRED G. MAYER: — 

M.E., Stevens Institute, Hoboken, N. J., 
1889 ; Assistant in Physics, Clark Uni- 
versity, 1889-90 ; Assistant in Physics, 
University of Kansas, 1890-92 ; Graduate 
Student in Zoology, Harvard University, 
1892-95 ; Museum Assistant in Charge of 
Radiates, Echinoderms, and Polype, and 
Assistant to Dr. Alexander Agassiz, 
1895- ; Sc.D., Harvard University, 1896 ; 
Member of : American Society of Natu- 
ralists, American Morphological Society, 
Boston Society of Natural History, Ameri- 
can Association for Advancement of Sci- 
ence ; President of the Cambridge Ento- 
mological Society. 

Author of : — 

Radiation and Absorption of Heat by 

Leaves. Am. Jour, of Sci., April, 

1893, Vol. 45, pp. 340-346. 
Some New Medusae from the Bahamas. 

Bidl. Mus. Comp. Zool. , 1894, Vol. 25, 

pp. 235-242, 3 pis. 
Color and Color-Patterns of Moths and 

Butterflies. Ibid., 1897, Vol. 30, pp. 

169-256, 10 pis. 
The Development of Wing Scales and their 

Pigment in Butterflies and Moths. 

Ibid., 1896, Vol. 29, pp. 209-236, 7 pis. 
A New Hypothesis of Seasonal Dimor- 
phism in Lepidoptera. Psyche, April- 
May, 1897, Vol. 8, pp. 47-50, 59-62. 
On Dactylometra. (With A. Agassiz.) 

Btill. Mus. Comp. Zool., 1898, Vol. 32, 

pp. 1-11, 13 pis. 
On Some Medusae from Australia. (With 

A. Agassiz.) Ibid., 1898, Vol. 32, pp. 

12-19, 3 pis. 
Acalephs from the Fiji Islands. (With 

A. Agassiz.) Ibid., 1899, Vol. 32, pp. 

151-189, 17 pis. 
On an Atlantic "Palolo" Worm. Ibid. 

(In press.) 
Medusae of the Atlantic Coast of North 

America. (With A. Agassiz.) Mem. 

Mus. Comp. Zool. 



Published Papers. 



521 



A. D. MEAD: — 

A.B., Middlebury College, 1890; A. M., 
Brown University, 1891 ; Fellow in Mor- 
phology, Clark University, 1891-92 ; 

Fellow in Biology, University of Chicago, 
1892-95 ; Ph.D., University of Chicago, 
1895 ; Instructor in Comparative Anatomy, 
Brown University, 1895-96 ; Associate 
Professor of Embryology and Neurology, 
ibid., 1897-. 

Author of : — 

Preliminary Account of the CeU-Lineage 
of Amphitrite and other Annelids. 
Jour, of Morph., Sept., 1894, Vol. 9, 
pp. 465-473. 

Some Observations on Maturation and 
Fecundation of Chaetopterus perga- 
mentaceus Cuvier. Ibid., Jan., 1895, 
Vol. 10, pp. 313-317. 

The Origin of the Egg Centrosomes. 
Ibid., Feb., 1897, Vol. 12, pp. 391-394. 

The Early Development of Marine Anne- 
lids. (Thesis.) 76i(^., May, 1897, Vol. 
13, pp. 227-326. 

The Origin and Behavior of the Centro- 
somes in the Annelid Egg. Ibid., 
June, 1898, Vol. 14, pp. 181-218, 4 pis. 

The Rate of Cell Division and the Function 
of the Centrosome. Woods Soil Biol. 
Lectures, 1896-97. Ginn & Co., Bos- 
ton, 1898, pp. 203-218. 

The Breeding of Animals at Woods Holl 
during the Month of April, 1898. 
Science, May 20, 1898, N. S., Vol. 7, 
pp. 702-704. 

Habits and Life History of the Starfish. I. 
2Sth Bep. of the Com. of Inland Fish- 
eries of B. I., 1898. 

Habits and Life History of the Starfish. 
II. S9th Bep. , ibid. , 1899. 

Peridinium and the "Red Water" in 
Narragansett Bay. Science, Nov 18, 
1898, N. S., Vol. 8, pp. 707-709. 

The Cell Origin of the Prototroch. Woods 
Holl Biol. Lectures, 1898. 

GEORGS F. METZLER: — 

A.B., Albert College, Ontario, Can., 
1880; Head Master, Port Dover High 
School, 1880-81; Professor of Mathe- 



matics, Albert College, 1881-84; A.M., 
Victoria College, 1883 ; Professor of 
Mathematics, Marietta College, 1889-90 ; 
Ph.D., Johns Hopkins University, 1891 ; 
Honorary Fellow^ in Psychology, 
Clark University, 1891-92 ; Docent in 
University of Chicago and Instructor in 
Mathematics, University of Michigan, 
1892-93 ; University of Gbttingen, 1893- 
94 ; University of Berlin, 1894-95 ; Asso- 
ciate in Mathematics, Queens College, 
1896-97 ; Assistant Pastor Methodist 
Church, Newburgh, Can., 1897-98 ; Pas- 
tor of Methodist Church, Wilberforce, 
Canada, 1898-. 

Author of: — 

Equations and Variables Associated with 
the Linear Differential Equation. An- 
nals of 3Iath., Vol. 9, pp. 171-178 ; 
Vol. 11, pp. 1-9. 

Surfaces of Rotation with Constant Meas- 
ure of Curvature and their Represen- 
tation on the Hyperbolic (Cayley's) 
Plane. Am. Jour, of Math., Jan., 1898, 
Vol. 20, pp. 76-86. 

WILLIAM H. METZLER: — 

A.B., University of Toronto, 1888; 
Science Master, Collegiate Institute, Inger- 
soU, Ont., 1888-89; Fellow in Mathe- 
matics, Clark University, 1889-92; 
Ph.D., Clark University, 1893 ; In- 
structor in Mathematics, Massachusetts 
Institute of Technology, 1892-94 ; Pro- 
fessor of Mathematics, Genesee Wesleyan 
Academy, 1894-95 ; Associate Professor 
of Mathematics, Syracuse University, 
1895-96 ; Professor of Mathematics, ibid., 
1896-; Member of : American Association 
for the Advancement of Science ; Ameri- 
can Mathematical Society ; Deutsche 
Mathematiker-Vereinigung ; Mathemat- 
ical Association (England) ; British As- 
sociation for the Advancement of Science ; 
London Mathematical Society. 

Author of : — 

On the Roots of Matrices. Am. Jour, of 
Math., Oct., 1892, Vol. 14, pp. 326- 
377. 



522 



Titles of 



On Certain Properties of Symmetric, Skew 
Symmetric, and Orthogonal Matrices. 
lUd., July, 1893, Vol. 15, pp. 274^-282. 

Homogeneous Strains. Annals of Math., 
Vol. 8, No. 5. 

On Compound Determinants. Am. Jour, 
of Math., Apra, 1894, Vol. 16, pp. 
131-150. 

Matrices which Represent Vectors. Tech- 
nology Quarterly, Vol. 6. No. 4. 

Some Notes on Symmetric Functions. 
Proc. London Math. Soc, March 11, 

1897, Vol. 28, pp. 390-393. 
Compound Determinants. Am. Jour, of 

Math., July, 1898, Vol. 20, pp. 263- 
272. 
A Theorem in Determinants. Ibid. , July, 

1898, Vol. 20, pp. 273-276. 

On the Excess of the Number of Combina- 
tions in a set which have an even 
number of inversions over those which 
have an odd number. (In press.) 

On the Roots of a Determinantal Equa^ 
tion. Am. Jour, of Math., Oct., 1899, 
Vol. 21, pp. 367-368. 

On a Determinant each of whose Elements 
is the Product of K Factors. (In 
press.) 

On a Theorem in Determinants related to 
Laplace's. (In press.) 

ADOLF MEYER: — 

Maturitatsexamen, Gymnasium, Zlirioh, 
1885 ; Medical Staatsexamen, Ztirich, 
1890 ; Graduate Student in Medicine, 
Paris, Edinburgh, and London, 1890-91 ; 
Neurological Work in the Laboratory of 
the Clinic of Psychiatry of Professor A. 
Forel, Ziirich, 1891 ; Neurological Student, 
Vienna, 1892 ; M.D., University of Ziirich, 
1892 ; Docent in Neurology, University of 
Chicago, and Pathologist, Illinois Hospital 
for the Insane, 1893-95 ; Director of the 
clinical and laboratory work, Worcester 
Insane Hospital, 1895- ; Docent in Psy- 
chiatry, Clark University, 1895-. 

Author of : — 

Mediciaische Studien in Paris, Edinburgh, 
und London. Correspondenz-Blatt 
fur Schweizer Aerzte, June 1, 1891, 



Vol. 21, pp. 350-357 ; June 15, pp. 
381-386 ; July 1, pp. 417-420. 

Ueber das Vorderhirn einiger ReptiUen. 
Zeitschrift fur wissenschaftliche Zo- 
ologie, 1892, Vol. 55, pp. 63-133, 2 
pis. 

Zur Homologie der Foruixoommissur und 
des Septum lucidum bei den Reptilien 
und Saugern. Anatomischer Anzeiger, 
March 15, 1895, Vol. 10, pp. 474-482. 

Neurological Work at Zurich. Journal of 
Comparative Neurology, 1893, Vol. 3, 
pp. 1-6, 41-44, 114-118. 

How Can We Prepare Neurological Ma- 
terial to the Best Advantage ? Jour- 
nal of Nervous and Mental Diseases, 
May, 1894, Vol. 19, pp. 277-291. 

Considerations on the Findings in the 
Spinal Cord of Three General Para^ 
lytios. Am. Jour, of Insanity, Jan., 
1895, Vol. 51, pp. 374-379. 

Mental Abnormalities in Children during 
Primary Education. , Tran. III. Soc. 
for Child Study, Dec, 1894, Vol. 1, 
No. 1, pp. 48-58. 

Schedule for the Study of Mental Abnor- 
malities in Children. Ibid., May, 
1895, Vol. 1, No. 2, pp. 53-57. 

On the Observation of Abnormalities of 
Children. Child Study Monthly, May, 
1895, Vol. 1, pp. 1-12. 

Report to the Governor of Illinois on the 
Treatment of the Insane. Compila- 
tion of Special Reports, etc., Spring- 
field, 111., 1894, pp. 18-29. 

A Few Demonstrations of Pathology of 
the Brain and Remarks on the Prob- 
lems connected with Them. Am. 
Jour, of Insanity, Oct., 1895, Vol. 52, 
pp. 243-249, 3 pis. 

On the Diseases of Women as a Cause of 
Insanity in the Light of Observations 
in Sixty-nine Autopsies. Tran. of the 
III. State Med. Soc, 1895. 

A Review of the Signs of Degeneration 
and of Methods of Registration. Am. 
Jour, of Insanity, Jan. , 1896, Vol. 52, 
pp. 344-363. 

Pathological Report of the Illinois Eastern 
Hospital for the Insane at Kankakee, 
111. Chicago, 1896, pp. 1-236, 16 pis. 



PuhlisTied Papers. 



523 



A Case of Landry's Paralysis, with Au- 
topsy. (With Dr. Th. Diller.) Am. 
Jour, of the Medical Sciences, April, 

1896, Vol. 115, pp. 404-413. 
Etiological, Clinical, and Pathological 

Factors in Diagnosis and Rational 
Classification of Infectious, Toxic, and 
Asthenic Diseases of the Peripheral 
Nerves, Spinal Cord, and Brain. Medi- 
cine, Detroit, Mich., Aug. 1896, Vol. 2, 
pp. 639-652. 
A Short Sketch of the Problems of Psy- 
chiatry. Am. Jour, of Insanity, April, 

1897, Vol. 53, pp. 538-549. 

General Paralysis and Other jSfervous and 
Mental Affections Following Syphilitic 
Infection. Yale Medical Journal, 
May, 1897, Vol. 3, pp. 311-317. 

Demonstration of Various Types of 
Changes in the Giant Cells of the 
Paracentral Lobule. Am. Jour, of 
Insanity, Oct. 1897, Vol. 54, pp. 221- 
226, 3 pis. 

Anatomical Findings in a Case of Facial 
Paralysis of Ten Days' Duration in a 
General Paralytic, with Remarks on 
the Termiiiation of the "Auditory" 
Nerves. Jour, of Experimental Medi- 
cine, Nov. 1897, Vol. 2, pp. 607-610, 
2 pis. 

Special Report of the Medical Depart- 
ment of the Worcester Lunatic Hos- 
pital. Annual Report, Oct. 1898, pp. 
20-27. 

Critical Review of the Data and General 
Methods and Deductions of Modern 
Neurology. Jour, of Comp. Neurol- 
ogy, Nov. -Dec, 1898, Vol. 8, pp. 113- 
148 ; 249-313, 7 pis. 

Critical Review of Recent Publications of 
Bethe and Nissl. Ihid., March, 1899, 
Vol. 9, pp. 38^5. 

Reviews in the Neurologisches Central- 
blatt. Psychological Beview, Am. Jour, 
of Insanity, Jour, of Nervous and Men- 
tal Disease. 

ARTHUR MICHAEL: — 

University of Heidelberg, 1873-75 ; Uni- 
versity of Berlin, 1875-78 ; :fecole de M^de- 
cine, 1879-80 ; Professor of Chemistry, 



Tufts College, 1881-89 ; Ph.D. (Honor- 
ary), Tufts College, 1889; Professor of 
Chemistry, Clark University, Sept.- 
Dec, 1889 ; Research Work in England, 
1890-94 ; Professor of Chemistry, Tufts 
College, 1894-. 

Author of : — 

Ueber die Einwirkung von Kaliumsulfhy- 

drat auf Chloralhydrat. Ber. d. deuts. 

chem. Gesellschaft, 1876, Vol. 9, pp. 

1267-1268. 
Ueber die Darstellung und Eigenschaften 

des Trijodresorcins. (With T. H. 

Norton.) Ibid., Vol. 9, pp. 1752-1753. 
Ueber die Einwirkung von wasserentzie- 

henden Mitteln auf Saureanhydride. 

(With S. Gabriel.) Ibid., 1877, Vol. 

10, pp. 391-393; 1551-1562, 2199- 

2210; 1878, Vol. 11, pp. 1007-1021, 

1679-1683. 
ZurDarstellungderParamidobenzoesaure. 

Ibid., 1877, Vol. 10, pp. 576-580. 
Ueber die Diamidosulfobenzid-Dicarbon- 

saure. (With T. H. Norton.) Ibid., 

Vol. 10, pp. 580-583. 
Zur Kenntniss der aromatischen Sulfone. 

(With A. Adair.) Ibid., Vol. 10, pp. 

583-587. 
Ueber die Einwirkung des Broms auf 

Aethylphtalimid. Ibid. Vol. 10, pp. 

1644-1645. 
Ueber die Einwirkung des Chlorjods auf 

aromatische Amine. (With L. M. 

Norton.) Ibid., 1878, Vol. 11, pp. 

107-116. 
Zur Kenntniss der aromatischen Sulfone. 

(With A. Adair.) Ibid., Vol. 11, pp. 

116-121. 
Ueber Benzylmethylglycolsaure. (With 

S. Gabriel.) Ibid., 1879, Vol. 12, pp. 

81^816. 
On the Action of Iodine Monocbloride 

upon Aromatic Acids. (With L. M. 

Norton.) Am. Chem. Jour., 1879, 

Vol. 1, pp. 255-267. 
On the Synthesis of Helicin and Phenol- 

glucoside. Ibid., Vol. 1, pp. 305-312. 
On a New Formation of Stilbene and some 

of its Derivatives. Ibid., Vol. 1, pp. 

312-316. 



524 



Titles of 



On Mono-Ethylphthalate. Ibid., 1880, 
Vol. 1, pp. 413-416. 

On a New Formation of Ethyl-Mustard 
Oil. Ibid., Vol. 1, pp. 416-118. 

On the Preparation of Methyl Aldehyde. 
Ibid., Vol. 1, pp. 418-420. 

On the " Migration of Atoms in the Mole- 
cule " and Reimer's Chloroform Alde- 
hyde Reaction. Ibid., Vol. 1, pp. 
420-426. 

On a- and 6-Monobromcrotonic Acids. 
(WithL. M. Norton.) Ibid., Vol. 2, 
pp. 11-19. 

Preliminary Note on the Synthesis of 
Methyloonine and Constitution of Co- 
nine. (With Charles Gxindelach.) 
Ibid., Vol. 2, pp. 171-172. 

Ueber die Einwirkung von aromatischen 
Oxysauren auf Phenole. Ber. d. 
deuts. chem. Gesellschaft, 1881, Vol. 
14, pp. 656-658. 

Ueber die Synthese des Methylarbutins. 
Ibid. Vol. 14, pp. 2097-2102. 

Zur Ivenntniss des Paraooniins. Ibid., 
Vol. 14, pp. 2105-2110. 

Ueber die Synthese des Salclns und des 
Anhydrosalicylglucosids. Ibid., 1882, 
Vol. 15, pp. 1922-1925. 

On the Action of Aromatic Oxy-acids on 
Phenols. Am. Chem. Jour., 1883, 
Vol. 5, pp. 81-97. 

On Some Properties of Phenylsulphona- 
cetio Ethers. (With A. M. Comey.) 
Ibid., Vol. 5, pp. 116-119. 

Synthetical Researches in the Glucoside 
Group. Ibid., Vol. 5, pp. 171-182. 

On the Formation of Crotonic and 6-Oxy- 
butric Aldehydes from Ethyl Alde- 
hyde. (With Adolph Kopp.) Ibid., 
Vol. 5, pp. 182-191. 

On the Action of Sodium Ethyl Oxide on 
Bromethylidenebromide. Ibid., Vol. 
5, pp. 192-197. 

A New Synthesis of AUantoin and Some 
Suggestions on the Constitution of 
Uric Acid. Ibid., Vol. 5, pp. 198- 
202. 

On a Convenient Method for Preparing 
Bromacetio Acid. Ibid., Vol. 5, pp. 
202-203. 

On Several Cases of Intermolecular Re- 



arrangement. Ibid., Vol. 5, pp. 203- 

205. 
On a New Synthesis of Cinnamic Acid. 

Ibid., Vol. 5, pp. 205-206. 
On the Action of Aldehydes on Phenols. 

Ibid., Vol. 5, pp. 339-349. 
Action of Ethylaldehyde on Orcin and 

Resorcin. (With A. M. Comey.) 

Ibid., Vol. 5, pp. 349-353. 
Some Convenient Quantitative Lectui-e 

Apparatus. Ibid., Vol. 5, pp. 353- 

359. 
Observations on the Action of Acetyl- 

chloride and Acetic Anhydride on 

Corn and Wheat Starch. Ibid., Vol. 

5, pp. 359-360. 
On the Constitution of Resocyanin. Ibid., 

Vol. 5, pp. 434-440. 
Ueber die optisch-inactive Asparaginsaure. 

(With J. E. Wing.) Ber. d. deuts. 

chem. Gesellschaft, 1884, Vol. 17, p. 

2984. 
On the Action of Sodium Phenylsulphin- 

ate on Methylene Iodide. (With G. 

M. Palmer.) Avi. Chem. Jour., 1884, 

Vol. 6, pp. 253-257. 
On the Conversion of Organic Isocyanates 

into Mustard Oils. (With G. M. 

Palmer.) Ibid., Vol. 6, pp. 257-260. 
Synthetical Researches in the Glucoside 

Group. Ibid., Vol. 6, pp. 336-340. 
On the Action of Methyl Iodide on As- 

paragine. (With J. E. Wing.) Ibid., 

1885, Vol. 6, pp. 419-422. 
On Some Properties of Phenylsulphona- 

cetic Ethers. (With G. M. Palmer.) 

Ibid., Vol.7, pp. 65-71. 
Note on the Constitution of the Addition- 
Product of Chlorhydric Acid to Ethyl- 
cyanide. (With J. P. Wing.) Ibid., 

Vol. 7, pp. 71-74. 
On the Decomposition of Cinchonine by 

Sodium Ethylate. Ibid., Vol. 7, pp. 

182-189. 
On Simultaneous Oxidation and Reduc- 
tion by Means of Hydrocyanic Acid. 

(With G. M. Palmer.) Ibid., Vol. 7, 

pp. 189-194. 
On the Action of Alkyl Iodides on Amido 

Acids. (With .T. F. Wing.) Ibid., 

Vol. 7, pp. 195-199. 



Published Papers. 



525 



On Eesacetophenone. CWitli G. M. 
Palmer.) lUd., Vol. 7, pp. 275-277. 

On Inactive Aspartic Acid. (With J. F. 
Wing.) Ibid., Vol. 7. pp. 278-281. 

Ueber die Einwirkung von Fiinffacli- 
Chlorphosphor auf die Aether organ- 
ischer Sauren. Ber. d. deuts. chem. 
Gesellschaft, 1886, Vol. 19, pp. 845- 
847. 

Ueber einen Zusammenhang zwischen 
Anilidbildung und der Constitution 
ungesattigter, mehrbasischer, organ- 
ischer Sauren. Ibid., Vol. 19, pp. 
1372-1375. 

Ueber einen Zusammenhang zwischen 
Anilidbildung und der Constitution 
ungesattigter, mehrbasischer, organ- 
ischer Sauren. (With G. M. Palmer. ) 
Ibid., Vol. 19, pp. 1375-1376. 

Ueber die Einwirkung des Anilins auf die 
Brommalein und Chlorfumarsaure. 
Ibid., Vol. 19, pp. 1377-1378. 

Zur Isomerie in der Zimmtsaurereihe. 
(With G. M. Brovme.) Ibid., Vol. 
19, pp. 1378-1381. 

Zur Isomerie in der Eettreihe. Ibid., 
Vol. 19, pp. 1381-1386. 

Ueber die Nitrirung des Phenylhydrazins. 
Ibid., Vol. 19, pp. 1368-1388. 

Zur Kenntniss der Einwirkung von Alde- 
hyden auf Phenole. (With J. P. Ry- 
der.) Ibid., Vol. 19, pp. 1388-1390. 

Die Citraconsaure als Reagenz zur Erken- 
nung und Scheidung der aromatischen 
Amine. Ibid., Vol. 19, pp. 1390-1392. 

Ueberfuhrung der a-Bromzimmtather in 
Benzoylessigather. (With G. M. 
Browne.) Ibid., Vol. 19, pp. 1392- 
1393. 

Zur Isomerie in der Zimmtsaurereihe. 
(With G. M. Browne.) Ibid., 1887, 
Vol. 20, pp. 550-556. 

Bemerkungen zu einer Abhandlung des 
Hrn. L. Claisen. Ibid., Vol. 20, pp. 
1572-1573. 

On the Addition of Sodium Acetacetic 
Ether and Analogous Sodium Com- 
pounds to Unsaturated Organic Ethers. 
Am. Chem. Jour., 1887, Vol. 9, pp. 
112-124. 

On Some New Reactions with Sodium 



Acetacetic and Sodium Malonic Ethers. 
Ibid., Vol. 9, pp. 124-129. 
On the Action of Aldehydes on Phenols. 
(With J. P. Ryder.) Ibid., Vol. 9, 
pp. 130-137. 
Researches on AUoisomerism. Ibid., Yo\. 

9, pp. 180-183. 
A Relation between the Constitution of 
Polybasic Unsaturated Organic Acids 
and the Formation of their Anilides. 
Ibid., Vol. 9, pp. 183-197. 
A Relation between the Constitution of 
Polybasic Unsaturated Organic Acids 
and the Formation of their Anihdes. 
(With G. M. Palmer.) Ibid., Vol. 9, 
pp. 197-204. 
On the Action of Phosphorus Pentachlo- 
ride on the Ethers of Organic Acids, 
and on some Derivatives of Acetic 
Acid. /6«., Vol. 9, pp. 205-217. 
On the Action of Phosphorus Pentachlo- 
ride on Acetanilide. Ibid., Yol. 9, pp. 
217-219. 
Preliminary Notes. Ibid., Vol. 9, pp. 

219-222. 
Researches on AUoisomerism. (With G. 
M. Browne.) Ibid., Vol. 9, pp. 274- 
289. 
Remarks on the Constitution of Levulinic 
and Maleic Acids. Ibid. , Vol. 9, pp. 
364-372. 
Ueber eine bequeme Darstellungsweise von 
bromirten Fettsauren. Jour. f. prak- 
tische Chemie, 1887, Vol.35, pp. 92-95. 
Das Verhalten von Essigsaure und einigen 
Derivaten derselben gegen Fiinffach- 
Chlorphosphor. Ibid., Vol. 35, pp. 
95-96. 
Ueber die Constitution der Trimethylen- 
tricarbonsaure. Ibid., Vol. 35, pp. 
132-136. 
Zur Kenntniss der Einwirkung des Funf- 
fach-Chloi'phosphors auf Acetanilid. 
Ibid., Yo\. 35, pp. 207-208. 
Ueber die Bildung des Indigblau aus 
Orthonitrophenylpropiolsaure mittelst 
Cyankalium. Ibid., Vol. 35, pp. 254- 
256. 
Ueber AUoisomerie in der Crotonsaure- 
reihe. (With G. M. Browne.) Ibid., 
Vol. 35, pp. 257-259. 



526 



Titles of 



Ueber die Addition von Natriumacetessig- 

und Natriummalonsaui-eathern zu den 

Aethern vmgesiittigter Sauren. Ihid., 

Vol. 35, pp. 349-356. 
Die Reduction von Alpha^ und AUoalpha- 

bromzimmtsauren zu Zimmtsaure. 

lUd., Vol. 35, pp. 357-358. 
Ueber aromatisohe Hydroxylamine. (With 

G. M. Browne.) Ibid., Vol. 35, pp. 

858-359. 
TTeber neue Reactioneu mit Natriumacet- 

essig- und Natriummalonsaureather. 

Ihid., Vol. 35, pp. 449-459. ' 
Ueber das Verhalten von Oxalsaureather 

zu Resorcin. Ibid., Vol. 35, pp. 510- 

512. 
Antwort auf sine Bemerkung von L. 

Claisen. Ibid., Vol. 36, pp. 113-114. 
Zur Isomerie in der Crotonsaurereilie. 

(With G. M. Browne. ) Ibid. , Vol. 36, 

pp. 174-176. 
Zur Constitution des Natriumaoetessig- 

athers. Ibid., 1888, Vol. 37, pp. 473- 

530. 
Ueber das Verhalten von. Natriummalon- 

ather gegen Eesorcinol. Ibid., Vol. 37, 

pp. 469-471. 
Zur AUoisomerie in der Crotonsaurereihe. 

(With H. Pendleton.) Ibid. , Vol. 38, 

pp. 1-5. 
Zur Kritik der Abhandlung von J. 

Wislicenus : ' ' Ueber die raumliche 

Anordnung der Atome in organisohen 

Molekiilen." Ibid., Vol. 38, pp. 6-39. 
Preliminary Note on the Constitution of 

Sodium Acetacetic and Malonic Ethers. 

Am. Chem. Jour., 1888, Vol. 10, pp. 

158-160. 
Bemerkung zu der Abhandlung von Otto 

und Rossing ilber die Ersetzbarkeit des 

Natriums im Natriumphenylsulfones- 

sigather durch Alkyle. Ber. d. dents. 

chem. Gesellschaft, 1890, Vol. 23, pp. 

669-671. 
On the Constitution of Sodium Acetacetic 

Ether. Am. Chem. Jour., 1892, Vol. 

14, pp. 481-544. 
On the Action of Acetic Anhydride on 

Phenylpropiolic Acid. (With J. E. 

Bucher.) Ibid., 1898, Vol 20, pp. 89- 

120. 



On the Formation of Imido-1, 2-Diazo. 

Derivatives fi-om Aromatic Azimides 

and Esters of Acetylenecarboxylic 

Acids. (With F. Luehn and H. H. 

Higbee.) Ibid., Vol. 20, pp. 377- 

395. 
Zur Sohmelzpunktsbestimmung von hoch- 

sohmelzenden mid sogen. unschmelz- 

baren organischen Verbindungen. Ber. 

d. deuts. chem. Gesellschaft, 1895, 

Vol. 28, pp. 1629-1633. 
Ueber die Addition von Schwefel zu un- 

gesattigten organischen Verbindungen. 

Ibid., Vol. 28, pp. 1633-1637. 
Ueber die Einwirkung von Essigsaurean- 

hydrid airf Sauren der Aoetylenreihel. 

(With J. E. Bucher.) Ibid., Vol. 28, 

pp. 2511-2512. 
Einwirkung v. Aethyljodid u. Zink auf 

A a /3-Fettester. Ibid., Vol. 29, p. 1791. 
Zur Kermtniss der Additionsvorgange bei 

den Natriumderivaten von Formyl- uud 

Acetessigestern, und Nitroathaneu. 

Ibid., Vol. 29, pp. 1794-1799. 
Zur Constitution der Oxalessigsaure. 

(With J. E. Bucher.) Ibid., Vol. 29, 

pp. 1792-1793. 
Ueber die Regelmassigkeiten bei der Anla^ 

gerung von Halogenverbindungen auf 

ungesattigten Sauren. Jour. f. praJct. 

Chemie, 1889, Vol. 40, pp. 171-179. 
Ueber die Einwirkimg von Jodwasserstoffi 

auf die Krotonsauren. Ibid., Vol. 40, 

pp. 95-96. 
Zur Kenntniss der Lavulinsaure und des 

Acetondiessigsauredilaktons. Ibid., 

Vol. 43, pp. 113-130. 
Ueber die Addition von Natriumacetessig- 

und Natriummalonsaureathem zu den 

Aethern ungesattigter Sauren. (With 

P. C. Freer.) Ibid., Vol. 39, pp. 390- 

395. 
Zur Kenntniss der Halogenentziehung bei 

organisohen a /3-Halogensaureathern. 

(WithO. Schulthess.) Ibid., Vol, 39, 

pp. 587-596. 
Ueber die Addition von Brom zu Acetylen- 

dicarbonsaure und deren Althylather. 

Ibid., Vol. 46, pp. 210-233. 
Ueber die Einwirkung von Natrium- 

athylat auf Dibrombemsteinsaure- 



Published Papers. 



527 



ather. (With C. C. Maisoli.) Ibid., 

Vol. 46, pp. 233-236. 
Ueber die Crotonsaure und Derivate der- 

seltien. (Witli 0. Schulthess.) Ihid., 

Vol. 46, pp. 236-266. 
TJeber die BUdung von fester Crotonsaure 

bei der Reduction von alio-a-Brom- 

und-clilorci'otonsaure. lUd., Vol. 46, 

pp. 266-272. 
Beitrage zur Kenntoiss einiger Homologen 

der Aepfelsaure. (With G. Tissot.) 

Ibid., Vol. 46, pp. 285-304. 
Ueber die Addition von Chlor zu mehr- 

basischen, ungesattigten Fettsauren. 

(With G. Tissot.) Ibid., Vol. 46, pp. 

381-427. 
Ueber die Addition von Natriumacetessig- 

und Natriumacetmalonatlier zu den 

Aethern ungesattigter Sauren. Ibid., 

Vol. 49, pp. 20-25. 
Beitrage zur Kenntniss der EingbUdung 

bei organischen, stickstofihaltigen Ver- 

bindungen. Ibid., Vol. 49, pp. 26-43. 
Untersuchungen iiber Alloisomerie. 

Ihid., Vol. 49, pp. 289-372. 
TJeber das Verhalten von Benzaldehyd 

gegen Phenol. Ibid., Vol. 57, 334- 

336. 
Ueber einige Gesetze und deren Anwen- 
dung in der organischen Chemie. 
Ibid., Vol. 60, pp. 286-470. 

ALBERT A. MICHELSON : — 

Midshipman, U. S. Naval Academy, 1873 
Instructor in Physics and Chemistry, ibid. 
1875-79 ; Nautical Almanac Office, Wash 
ington, 1880 ; University of Berlin, 1880 
University of Heidelberg, 1881 ; College 
de France, 'fecole Polytechnique, 1882 
Professor of Physics, Case School of Ap- 
plied Science, Cleveland, 0., 1883-89 
Corresponding Member, British Associa- 
tion for the Advancement of Science, 1884 
Associate Fellow of American Academy 
of Arts and Sciences, 1885; Ph.D. 
(Honorary), Western Eeserve University 
1886 ; and Stevens Institute, 1887 ; Vice- 
President, American Association for the 
Advancement of Science, ibid. ; Member 
of National Academy of Sciences, 1888 ; 
Rumford Medal, 1889; Professor of 



Physics, Clark tTniversity, 1889-92 ; 

Head Professor of Physics, University of 
Chicago, 1892- ; Bureau International des 
Poids et Measures, 1892-93 ; Member, 
Soci^t^ Frangaise de Physique, 1898 ; Fel- 
low, Royal Astronomical Society, 1896 ; 
Foreign Member, Soci^t^ Hollandaise des 
Sciences, 1897 ; Honorary Member, Cam- 
bridge Philosophical Society, ibid. ; Mem- 
ber (for the United States) of the In- 
ternational Committee of Weights and 
Measures, ibid. ; Lowell Lecturer, 1899 ; 
Sc.D. (Honorary), University of Cambridge 
(England); Honorary Member Royal In- 
stitute, 1899. 

Author of : — 

Esperimental Determination of the Veloc- 
ity of Light. Papers I. and II. Froc. 
A. A. A. S., 1879 and 1880. 
The Relative Motion of the Earth and 
the Lmniniferous Ether. Am. Jour, 
of Set, 1881, Vol. 22, pp. 120-129. 
A New Sensitive Thermometer. Jour. 

de Physique, 1882. 
Interference Phenomena in a New Form 
of Eefractometer. Am. Jour, of Sci., 
May, 1882, Vol. 23, pp. 395-400. 
A Method of Determining the Rate of 
Tuning-Forks. Am. Jour, of Sci., 
Jan., 1883. 
Experimental Determination of the Veloc- 
ity of Light. Third Paper. Astron. 
Papers, Nautical Almanac, Vol. 2. 
Velocity of Light In Carbon Disulphide 
and Velocity of Red and Blue Light 
in Same. Ibid. 
M. Wolf's Modification of Foucault's 
Apparatus for the Measurement of 
the Velocity of Light. Nature, May 7, 
1885, Vol. 32, pp. 6-7. 
Influence of Motion of the Medium on 
the Velocity of Light. Am. Jour, of 
Sci., May, 1886, Vol. 31, pp. 377-386. 
On the Relative Motion of the Earth and 
the Luminiferous Ether. (With E. 
W. Morley.) Philosophical Magazine, 
5th ser., Dec, 1887, Vol. 24, pp. 
449-463. 
On a Method for Making the Wave 
Length of Sodium Light the Actual 



528 



Titles of 



and Practical Standard of Length. 
(With E. W. Morley.) Am. Jour, of 
Sci., Dec, 1887, Vol. 34, pp. 427-430. 
Philosophical Magazine, 5th ser., 
Dec, 1887, Vol. 24, pp. 463-466. 

On the Feasibility of Establishing a Light 
Wave as the Ultimate Standard of 
Length. (With E. W. Morley.) Am. 
Jour, of Sci., 3rd ser., Sept., 1889, 
Vol. 38, pp. 181-186. 

Measurement by Light Waves. Ibid., 
Feb., 1890, Vol. 39, pp. 115-121. 

A Simple Interference Experiment. Ibid. , 
March, 1890, Vol. 39, pp. 216-218. 

Application of Interference Methods to 
Astronomical Measurements. Philo- 
sophical Magazine, 5th ser., July, 1890, 
Vol. 30, pp. 1-21. 

Visibility of Interference Fringes in the 
Focus of a Telescope. Ibid., March, 
1891, Vol. 31, pp. 256-259. 

Application of Interference Methods to 
Spectroscopic Measurements. Ibid. , 
April, 1891, Vol. 31, pp. 338-346. 

Measurement of Jupiter's Satellites by 
Interference. Mem. Astr. Soc. of the 
Pacific, 1891. 

Les m^thodes interf^rentielles en m^trol- 
ogie et l'6tablissement d'une longueur 
d'onde comme unitfi absolue de 
longueur. Bev. Gen. des Sciences, 30 
Juin, 1893. Translation in Nature, 
Nov. 16, 1893. Abstracts in Comptes 
Eendus and Soc. de Physique. 

Determination exp6rimentale de la valeur 
du mfetre en longueur d'ondes lumi- 
neuses. Travaux et Slemoires du 
Bureau International des Poids et 
Mesures, Paris, 1895, Vol. 11, pp. 3-85. 

On the Broadening of Spectral Lines by 
Temperature and Pressure. Astro- 
physical Journal, Nov., 1895. 

On the Conditions which Affect the Spec- 
trum Photography of the Sun. Ibid., 
Jan., 1895. 

On the Limit of Visibility of Fine Lines 
in a Telescope. Ihid., June, 1895. 

The Relative Motion of the Earth and the 
Ether. Am. Jour, of Sci., 4th ser., 
1897, Vol. 3. pp. 475-478. 

Eadiation in a Magnetic Field, Philo- 



sophical Magazine, 5th ser., July, 1897, 
Vol. 44, pp. 109-115. 

A New Harmonic Analyser. (With S. W. 
Stratton.) Am. Jour, of Sci., 4th 
ser., Jan., 1898, Vol. 5, pp. 1-13. 

A Spectroscope without Prisms or Grat- 
ings. Ibid., 4th ser., March, 1898, Vol. 
5, pp. 215-217. 

Radiation in a Magnetic Field, Astro- 
physical Jour^ial, Feb., 1898. 

The Echelon Spectroscope. Ibid., June, 
1898. 

Nouvelle M6thode de tracer et d' observer 
des divisions de precision, form^es par 
des traits lumineux sur fond noir. 
Travaux et Memoires du Bureau 
International des Poids et Mesures, 
Paris, 1899. 

DICKINSON SERGEANT MILLEU: 

University of Pennsylvania, 1885-88 ; 
Fellow in Philosophy, Clark Univer- 
sity, 1889-90 ; Morgan Fellow, Har- 
vard University, 1890-91 ; Walker Fellow, 
ibid., 1891-92 ; A.B. and A.M., ibid., 
1892 ; University of Berlin, 1892-93 ; 
Ph.D., University of Halle, 1893 ; Asso- 
ciate in Philosophy, Bryn Blawr College, 
1893-98 ; Instructor, Harvard Univer- 
sity, for the year 1899-1900 ; Member of 
American Psychological Association. 

Author of : — 

The Meaning of Truth and Error. Phil- 
osophical Beview, July, 1893, Vol. 2, 
pp. 408-425. 

The Confusion of Function and Content 
in Mental Analysis. Proc. Am. Psy. 
Ass'n, Dec, 1893, and Psychological 
Beview, Nov., 1895, Vol. 2, pp. 535- 
550. 

The Relations of "Ought" and "Is." 
Internat. Jour, of Ethics, July, 1894, 
Vol. 4, pp. 499-512. 

Desire as the Essence of Pleasure. Proc. 
Am. Psy. Ass''n, Dec, 1894. Psycho- 
logical Beview, March, 1895, Vol. 2, 
pp. 164^165. 

"The Will to Believe" and the Duty to 
Doubt. Internat. Jour, of Ethics, 
Jan., 1899, Vol. 9, pp. 169-195. 



Published Papers. 



529 



Professor James on Philosophical Method. 
Philosophical Beview, March, 1899, 
Vol. 8, pp. 166-179. 

■WILLIAM S. MILLER: — 

M.D., Yale Medical School, 1879; Prac- 
tising Physician, ibid., 1879-86; College 
of Physicians and Surgeons, New York, 
1886-87 ; Lecturer in Microscopical Teoh- 
■ nique, Mt. Holyoke College, 1887-88 ; 
Pathologist, City Hospital and Memorial 
Hospital, "Worcester, Mass., 1888-91 ; 
Scholar in Anatomy, Clark Univer- 
sity, 1889-91 ; Fellow, 1891-92 ; In- 
structor in Biology, University of Wis- 
consin, 1892-93 ; Instructor in Vertebrate 
Anatomy, ibid., 1893-95 ; on leave of 
absence, University of Leipzig, 1895-96 ; 
Assistant Professor of Vertebrate Anat- 
omy, University of Wisconsin, 1895- ; 
Fellow, Massachusetts Medical Society, 
Fellow, A. A. A. S. ,- Member Anatomische 
Gesellschaf t. Member Wisconsin Academy 
of Arts and Sciences. 

Author of : — 

The Lobule of the Lung and its Blood- 
vessels. Anat. Anzeiger, 1892, Vol. 7, 
pp. 181-190. 

The Structure of the Lung. Jour, of 
Morph., April, 1893, Vol. 8, pp. 165- 
188. 

On the So-called Incas Eyes. Science, 
Feb. 10, 1893, Vol. 21, pp. 74-76. 

The Anatomy of the Lung. Bef. Hand- 
book of the Med. Sciences, 1893, Vol. 
9, pp. 571-576. 

The Anatomy of the Heart of Cambarus. 
Trans. Wis. Acad, of Sciences, Arts, 
and Letters, 1895, Vol. 10, pp. 327- 
338. 

The Relation between the Cortex and 
Medulla in the Cat's Kidney, and an 
Estimation of the Number of Glumer- 
uli. Ibid., pp. 525-538. 

The Lymphatics of the Lung. Anat. An- 
zeiger, June 4, 1896, Vol. 12, pp. 110- 
114. 

HALCOTT C. MORENO: — 

A.B., University of Georgia, 1893 ; A.M., 
ibid., 1894; B.L., ibid., 1896; Tutor in 
2m 



Mathematics, ibid., 1893-97; Scholar 
in Mathematics, Clark University 
1897-98 ; FeUow, 1898-99. 

SAMUEL P. MULLIKEN: — 

S.B., Massachusetts Institute of Tech- 
nology, 1887 ; Assistant in Chemistry, 
University of Cincinnati, 1887-88 ; Gradu- 
ate Student, University of Leipzig, 1888- 
90 ; Ph.D., University of Leipzig, 1890 ; 
Fellow in Chemistry, Clark Univer- 
sity, Jan.-June, 1891 ; Associate in 
Chemistry, Bryn Mawr College, 1891-92 ; 
Instructor in Chemistry, Clark Uni- 
versity, 1892-94 ; Research Assistant 
to Professor AVolcott Gibbs, Newport, 
R.I., 1894-95 ; Instructor in Organic 
Chemistry, Massachusetts Institute of 
Technology, 1895-. 

Author of : — 

Ueber die Konstitution der Chlorzimmt- 
sauren. (Inaugural-dissertation der 
Universitat Leipzig.) Leipzig, 1890. 
57 pp. 

The Geometrical Isomerism of the Chlor- 
cinnamic Acids. Technology Quar- 
terly, 1891, Vol. 4, pp. 170-177. 

A New Class of Organic Electrosyntheses. 
Am. Chem. Jour., June, 1893, Vol. 15, 
pp. 323-333. 

Laboratory Experiments on the Class Re- 
actions of Organic Substances and their 
Identification. (With A. A. Noyes.) 
First edition, 17 pp., Maclachlan, 
Boston, 1896; second edition, 38 pp., 
1897, and third edition, 30 pp., 1898. 
Chem. Publishing Company, Eastou, 
Pa. 

A Simple Color Reaction for Methyl Al- 
cohol. (With H. Scudder.) Am. 
Chem. Jour., March, 1899, Vol. 21, 
pp. 266-271. 

Reactions for the Detection of the Nitro- 
group. (With E. R. Barker.) Ibid., 
pp. 271-276. 

F. VTILLIAM MUTHMANN: — 

Assistant in Analytical Chemistry, Uni- 
versity of Munich, 1884-86 ; Ph.D., Uni- 
versity of Munich, 1886; Instructor in 



530 



Titles of 



Chemistry and Crystallography, ihid., 
1887-89 ; Docent in Chemistry, Clark 
University, 1889-91 ; Assistant In 
Cheiaistry, Aoademy of Science, Munich, 
1891-94 ; Docent in Chemistry, University 
of Munich, 1894-95 ; Professor of Inor- 
ganic and Analytical Chemistry, ibid., 
1895-. 

Author of : — 

Ueber niedere Oxyde des Molybdans. 

(Inaugural dissertation.) Liehig^sAn- 

nalen, 1887, Vol. 238, pp. 108-137. 
Ueber Polymorphic und Mischkrystalle 

einiger organischer Substanzen. Zeits. 

f. Krystallographie, 1889, Vol. 15, pp. 

60-79. 
Krystallographisch-chemische Notizen. 

Ibid., 1888, Vol. 15, pp. 387^03. 
Krystallographisohe Untersuchung der 

Phtalsaure, und einigen Derivate der- 

selben. (With W. Ramsay.) Ibid., 

1889, Vol. 17, pp. 73-84. 
Messelit, ein neues Mineral. Ibid., 1889, 

Vol. 17, pp. 93-94. 
Untersuchungen fiber den Schwefel und 

das Selen. Ibid., 1890, Vol. 17, pp. 

336-367. 
Zur Frage der Silberoxydulverbindungen. 

Ber. d. deuts. chem. Gesellschaft, 1887, 

Vol. 20, pp. 983-990. 
Krystallographisohe Untersuchung einiger 

Derivate der Terephtalsaure. Zeits. f. 

Krystallographie, 1890, Vol. 17, pp. 

460-483. 
Ueber Isomorphimus einiger organischer 

Substanzen. Ibid., 1891, Vol. 19, pp. 

357-367. 
Bemerkung iiber den rothen Phosphor. 

Zeits. f. anorg. Chemie, 1893, Vol. 4, 

pp. 303-304. 
Untersuchungen iiber das Selen. (With 

Dr. J. Schafer.) Ber. d. deuts. chem. 

Gesellschaft, 1893, Vol. 26, pp. 1008- 

1016. 
Erne bequeme Methode zur Darstellung 

von Baryumpermanganat. Ibid., pp. 

1016-1018. 
Ueber die Eeindarstellung von Rubidium- 

salzen. Ibid., pp. 1019-1020. 
Berichtigung. Ibid., pp. 1425-1426. 



Beitrage zur Volumtheorie der Krystalli- 
sirten Korper. Zeits. f. Ki~ystallogra- 
phie, 1894, Vol. 22, pp. 497-551. 

Ueber die Loslichkeit der Mischkrystalle 
einiger isomorpher Salzpaare. (With 
Dr. O. Kuntze.) Ibid., 1894, Vol. 23, 
pp. 368-378. 

Ueber den sogenannten Schneebergit. 
Ibid., 1895, Vol. 24, pp. 58^-586. 

Schwefelstickstoff. Ber. d. dents, chem. 
Gesellschaft, 1896, Vol. 29, pp. 340- 
343. 

Zur quant. Best, und Scheidung des Kup- 
fers. Zeits. f. anorg. Chemie, 1896, 
Vol. 11, pp. 268-271. 

Ueber einige Verbindungen des Phosphors 
und Selens. Ibid., Vol. 13, pp. 191-199. 

Stickstoffpentasulfld. Ibid., Vol. 13, pp. 
200-208. 

Loslichkeit des Schwefels Ceroxyduls in 
Wasser. Ibid. , 1897, Vol. 16, pp. 450- 
462. 

Zusammensetzung einiger TeUiuTminera^ 
len. Zeits. f. Krystallographie, 1898, 
Vol. 29, pp. 140-145. 

Ueber Permolydate. Zeits. f. anorg. 
Chemie, 1898, Vol. 17, pp. 73-81. 
Also Ber. d. deuts. chem. Gesellschaft, 
1898, Vol. 31, pp. 1836-1844. 

Doppelthiosulfate von Kupfer und Ka- 
lium. Ber. d. deuts. chem. Gesell- 
schaft, 1898, Vol. 31, pp. 1732-1735. 

JOHN U. NEP: — 

A.B., Harvard University (with Honors 
in Chemistry), 1884; Kirkland Fellow. 
ibid., 1884-87; University of Munich, 
1884-87 ; Ph.D., University of Munich 
1886 ; Professor and Director of Chemical 
Laboratory, Purdue University, 1887- 
Assistant Professor of Chemistry, 
Clark University, 1889-92 ; Professor of 
Chemistry and Director of the Kent Chemi- 
cal Laboratory, University of Chicago, 
1892-96 ; Head Professor of Chemistry 
and Director of the Kent Chemical Lab- 
oratory, ibid., 1896-. 

Author of : — 

The Volumetric Determination of Com- 
bined Nitrous Acid. (With Dr. Kin- 



Published Papers. 



531 



nicutt.) Am. Chem. Jour., Nov. 1883, 
Vol. 5, pp. 388-389. 

Ueber einige Derivate des Durols. Ber. 
d. dents, chem. Gesellschaft, 1885, Vol. 
18, pp. 2801-2807. 

Ueber Benzocliinoncarbonsaureii. Ibid., 
pp. 3496-3499. 

Ueber Benzochinoncarbonsauren. Lie- 
big's Annalen, 1887, Vol. 237, pp. 1- 
39. 

Ueber Py-S-Phenylchinaldinsaure und 
Py-3-Phenylchinolin. (With Dr. Koe- 
nigs.) Ber. d. deuts. chem. Gesell- 
schaft, 1886, Vol. 19, pp. 2417-2432. 

Ueber des Py-3-Phenylohinolin und Py- 
3-B-Dicliinolyle. (WlthDr. Koenigs.) 
Ibid., 1887, Vol. 20, pp. 622-636. 

Notiz iiber die Cinchoninsaure. (Witli 
W. Muthmaim.) Ibid., 1887, Vol. 20, 
pp. 636-638. 

Nltranilsaure aus Chloranil. Ibid., 1887, 
Vol. 20, pp. 2027-2031. 

On Tautomeric Compounds. Part I. 
Am. Chem. Jour., Jan., 1889, Vol. 
11, pp. 1-17. 

The Constitution of the Anilic Acids. 
Ibid., pp. 17-26. 

Ueber tautomere Korper. Liebig''s An- 
nalen, 1890, Vol. 258, pp. 261-318. 

Die Constitution des Benzochinons. 
Jour. f. xnaktische Chemie, 1890, Vol. 
42, pp. 161-188. 

On Tautomeric Compounds. Part II. 
Am. Chem. Jour., June, 1890, Vol. 12, 
pp. 379-425. 

The Constitution of Benzoquinone. Part 

I. Ibid., July, 1890, Vol. 12, pp. 
463-488. 

Zur Kenntniss des Acetessigathers. Lie- 
big's Annalen, 1891, Vol. 266, pp. 
52-188. 

The Constitution o£ Benzoquinone. Part 

II. Am. Chem. Jour., June, 1891, 
Vol. 13, pp. 422-428. 

Ueber das zweiwerthlge Kohlenstoffatom. 
Erste Abh. Liehig's Annalen, 1892, 
Vol. 270, pp. 267-335. Also in Proc. 
of Am. Acad, of Arts and Sciences, on 
Bivalent Carbon, for 1892, Vol. 27, 
pp. 102-162. 

Zur Kenntniss des Acetessigathers. Lie- 



big's Annalen, 1893, Vol. 276, pp. 

200-245. 
Ueber die 1.3 Diketone. Ibid., 1893, Vol. 

277, pp. 59-78. 
Ueber die Constitution der Salze der 

Nitroparaffine. Ibid., 1894, Vol. 280, 

pp. 263-291. Also in Proc. of Am. 

Acad, of Arts and Sciences, 1894, Vol. 

29, pp. 124-150. 
Ueber das zvfeiwerthige Kohlenstoffatom. 

Zweite Abh. Liebig's Annalen, 1894, 

Vol. 280, pp. 291-342. Also in Proc. 

of Am. Acad, of Arts and Sciences, 

1894, Vol. 29, pp. 151-19.3. 

Ueber das zweiwerthlge Kohlenstoffatom. 
Dritte Abh. Die Chemie des Cyans 
und des Isocyans. Liebig's Annalen, 

1895, Vol. 287, pp. 265-359. 

Ueber das zweiwerthlge Kohlenstoffatom. 
Vierte Abh. Die Chemie des Me- 
thyleus. Ibid., 1897, Vol. 298, pp. 
292-374. 

Notiz tlber die Pormhydroxamsaure. Ber. 
d. deuts. chem. Gesellschaft, 1898, Vol. 
31, pp. 2720-2721. 

Ueber das Phenylaoetylen, seine Salze, 
und seine Halogen Substitutions Pro- 
dukte. Liebig's Annalen der Chemie, 
1899, Vol. 308, pp. 264-328. 

Ueber das Verhalten der tri- und tetra- 
halogen-substituirten Methane. Ibid., 
1899, Vol. 308, pp. 329-333. 

Dissociationsvorgange bei den Alkyla- 
theon der Saltpetersaure, der Schwe- 
felsaure und der Halogenwasserstoff- 
sauren. Ibid., 1899, Vol. 309, pp. 
126-189. 

HERBERT NICHOLS:— 

B.S., Worcester Polytechnic Institute, 
1871 ; Fellow in Psychology, Clark 
University, 1889-91; Ph.D., Clark 
University, 1891; Instructor in Psy- 
chology, Harvard University, 1891-93 ; 
Lecturer in Psychology, Johns Hopkins 
University, 1895-96; Member American 
Society of Naturalists, 1890; Member 
American Psychological Association, 1892. 

Author of : — 

The Psychology of Time. Am. Jour, of 
Psy., Feb., 1891, Vol. 3, pp. 453-529 ; 



532 



Titles of 



AprU, 1891, Vol. 4, pp. 60-112. Henry 
Holt & Co., N. y., 1891, 140 pp. 

The Origin of Pleasure and Pain. Philo- 
sophical Review, Jvlj, 1892, Vol.1 .,pp. 
403-432; Sept., 1892, Vol. 1., pp. 518- 
534. 

Experiments upon Pain. Beport First An. 
Mtg. Am. Psy. Assn., Dec, 1892. Mac- 
mUlan&Co., N. Y., 1894. 

Perceptions of Rotation. Ibid., Dec, 1892. 
Blacmillan & Co., N. Y., 1894. 

Primary Education. Beport Special Cor- 
respondence, Feb., 1893. Educational 
Club, Philadelphia, 1893. 

The Harvard Psychological Laboratory. 
McClure's Magazine, Oct., 1893, Vol. 1, 
pp. 399-409. 

The Promise in Mental Science. Ibid., 
Jan., 1894, Vol. 2, pp. 202-203. 

Beitrage zur Psychologic des Zeitsinns, 
and Untersuchungen zur Psychologie 
und ^sthetik des Rhythmus. By 
Ernst Meumann. Review. Psycho- 
logical Review, Nov., 1894, Vol. 1, pp. 
638-641. 

Our Notions of Number and Space. Ginn 
& Co., Boston, 1894. 201 pp. 

The Motor Povcer of Ideas. Philosophical 
Review, March, 1895, Vol. 4, pp. 174- 
185. 

William James. (Biographical Sketch.) 
The Book Buyer, March, 1895, Vol. 12, 
pp. 61-63. 

The "Feelings." Philosophical Review, 
Sept., 1895, Vol. 4, pp. 506-530. 

Pain Nerves. (Discussion.) Psychologi- 
cal Review, Sept., 1895, Vol. 2, 487- 
490. 
Psychology and Education. The Citizen, 
Dec, 1895, Vol. 1, pp. 229-230. Uni- 
versity Extension Study, Philadelphia. 

Pain Nerves. (Discussion.) Psychologi- 
cal Review, May, 1896, Vol. 3, pp. 309- 
313. 

Fear. By Angelo Mosso. Review. Ibid., 
July, 1896, Vol. 3, pp. 445-447. 

TJeber Raumwahrnehmungen im Gebiete 
des Tastsinnes. By Chas. Hubbard 
Judd. Review. Ibid., Sept., 1896, 
Vol. 3, pp. 577-578. 

Professor Baldwin's New Factor in Evo- 



lution. The American Naturalist, 
Sept., 1896, Vol. 30, pp. 697-710. 

Further Comments on Professor Baldwin's 
New Factor in Evolution. Ibid., 
Nov., 1896, Vol. 30, pp. 951-954. 

The Biologic Origin of Mental Variety, or 
How We came to Have Minds. Ibid., 
Dec, 1896, Vol, 30, pp. 963-975 ; Jan., 
1897, Vol. 31, pp. 3-16. 

The Psycho-Motor Problem. Am. Jour. 
of Insanity, July, 1897, Vol. 54, pp. 59- 
80. 

Psychology and Physiology. Ibid., Oct., 

1897, Vol. 54, pp. 181-200. 

The Psychology of the Emotions. By 
Th. Ribot. Review. /6iU, Oct., 1897, 
Vol. 54, pp. 266-270. 

Hallucinations and Illiisions. By Ed- 
mund Parish. Review. Ibid., Jan., 

1898, Vol. 54, pp. 472-474. 

The New Psychology. By E. W. Scrip- 
ture. Review. Ibid., Jan., 1898, 
Vol. 54, pp. 474-475. 

The Psychology of Suggestion. By Boris 
Sidis. Review. Ibid., April, 1898, 
Vol. 54, pp. 643-644. 

The Genesis and Dissolution of the Fac- 
ulty of Speech. By Joseph CoUins. 
Review. Ibid., July, 1898, Vol. 55. 
p. 184. 

THOMAS F. NICHOLS: — 

A.B., Bowdoin College, 1892 ; Scholar in 
Mathematics, Clark University, 1892- 
93; Fellow, 1893-95; Ph.D., Clark 
University, 1895 ; Assistant in Mathe- 
matics, University of Wisconsin, 1895-96; 
Assistant Professor of Mathematics, Ham- 
ilton College, 1896-. 

Author of : — 

On Some Special Jacobians. Mathemati- 
cal Review, July, 1896, Vol. 1, pp. 
60-80. 

On the Generation of Certain Curves of the 
Fifth and Sixth Orders. Ibid., April, 
1897,Vol. 1, pp. 141-153. 

ARTHUR A. NOYES: — 

S.B., Massachusetts Institute of Tech- 
nology, 1886; S.M., ibid., 1887 ; Assistant 



Published Papers. 



533 



in Chemistry, t6i(?., 1887-88; Pli.D., 
University of Leipzig, 1890 ; Instructor in 
Cliemistry, Massachusetts Institute of 
Technology, 1890-93 ; Non-resident 
Lecturer in Physical Chemistry, Clark 
University, 1892-94 ; Assistant Pro- 
fessor of Chemistry, Massachusetts Insti- 
tute of Technology, 1893-97; Associate 
Professor of Organic Chemistry, ibid,., 
1897-99; Professor of Theoretical and Or- 
ganic Chemistry, i6id, 1899-. 

Author of : — 

On the Action of Heat upon Ethylene. 
(With L. M. Norton.) Am. Chem. 
Jour. Oct., 1886, Vol. 8, pp. 362- 
364. 

The Constitution of Benzol. Technology 
Quarterly, 1887, Vol. 1, pp. 79-90. 

On the Action of Heat on Isobutylene. 
lUd., pp. 278-281. 

Note on the Butines. (With L. M. Nor- 
ton.) Am. Chem. Jour., Nov., 1888, 
Vol. 10, pp. 430-433. 

An Index to the Literature of the Butines 
and their Halogen Addition Products. 
Technology Quarterly, 1888, Vol. 2, 
pp. 112-122. 

Ueber die Abweichungen von den Gasge- 
setzen in Losungen. Zeits. f. physik. 
Chemie, 1890, Vol. 5, pp. 53-67. 

Ueber die gegenseitige Beeinflussung der 
Lbslichkeit von dissociierten Korpern. 
Ibid., 1890, Vol. 6, pp. 241-267. 

Ueber vermehrte Loslichkeit. Anwen- 
dung der Gefrierpunktsbestimmungen 
zur Ermittelung der Vorgange in 
Losung. Ibid., 1890, Vol. 6, pp. 385- 
402. 

Ueber die Bestimmung der elektrolyti- 
schen Dissociation von Salzen mittels 
Loslichkeitsversuche. Ibid., 1892, 
Vol. 9, pp. 603-632. Translation in 
Technology Quarterly, 1891, Vol. 4, 
pp. 259-291. 

Ueber die Wasserstoffionabspaltung bei 
den sauren Salzen. Ibid., 1893, Vol. 
11, pp. 495-500, Translation in Tech- 
nology Quarterly, 1892, Vol. 5, pp. 342- 
349. 

Influence of the Introduction of a Sul- 



phonic Acid Group upon the Power of 
a Developer. (With W. K. Gay lord.) 
Technology Quarterly, 1893, Vol. 6, pp. 
60-61. 

Ueber die elektrolytische Reduction des 
Nitrobenzols in Schwefelsaurelosung. 
(With A. A. Clement.) Ber. d. deuts. 
chem. Gesellschaft, 1893, Vol. 26, pp. 
990-992. Translation in Technology 
Quarterly, 1893, Vol. 6, pp. 62-64. 

Ueber die Bestimmung der elektrolyti- 
schen Dissociation von Salzen mittels 
Loslichkeitsversuche. Zeits. f. phy- 
sik. Chemie, 1893, Vol. 12, pp. 162-166. 
Translation in Technology Quarterly, 

1893, Vol.6, pp. 237-240. 
Loslichkeit des sauren Kaliumtartrats 

bei Gegenwart anderer Salze. (With 

A. A. Clement.) Zeits. f. physik. 

Chemie, 1894, Vol. 13, pp. 412-416. 
Die Wassei-stoffionabspaltung bei dem 

sauren Kaliumtartrat. Zeits. f. physik. 

Chemie, 1894, Vol. 13, pp. 417-418. 
Kryoskopische Untersuchungen mit Alu- 

minaten und Boraten von Alkalime- 

tallen. (With W. R. Whitney.) Ibid., 

1894, Vol. 15, pp. 694-698. 

The Electrolytic Reduction of Paranitro- 
benzoic Acid in Sulphuric Acid Solu- 
tion. (With A. A. Clement.) Am. 
Chem,. Jour., Nov., 1894, Vol. 16, pp. 
511-513. 
Eine Priif ung der Principe der Loslichkeits- 
beeinflussung und ein Vergleich der 
daraus imd aus der elektrischen Leit- 
fahigkeit berechneten Dissociations- 
werte. (With C. G. Abbot.) Zeits.f. 
physik. Chemie, 1895, Vol. 16, pp. 
125-138. Translation in Technology 
Quarteriy, 1895, Vol. 8, pp. 47-62. 

Die Geschvrindigkeit der Reaktion 
zwischen Zinnchlorur und Eisen- 
chlorid. Eine Reaktion dritter Ord- 
nung. Zeits. f. physik. Chemie, 1895, 
Vol. 16, pp. 546-561. 

Synthesis of Diphenylbiphenyl and its 
Identification as Benzerythrene. 
(With Rolfe M. Ellis.) Am. Chem. 
Jour., Oct., 1895, Vol. 17, pp. 620-622. 
Also in Technology Quarterly, 1895, 
Vol. 8, pp. 178-180. 



534 



Titles of 



Die Gesohmndigkeit der Hydrolyse des 
Salicins duroh Sauren. (With W. T. 
Hall.) Zeits.f. physik. Chemie, 1895, 
Vol. 18, pp. 240-244. Translation in 
Technology Quarterly, 1895, Vol. 8, 
pp. 283-293. 

Beitrag zur Kenntniss der Gesetze der 
Geschwindigkeit von polymolekularen 
Keaktionen. (With W. O. Scott.) 
Zeits. f. physik. Chemie, 1895, Vol. 
18, pp. 122-132. 

The Electrolytic Reduction of Paranitro 
Compounds in Sulphuric Acid Solu- 
tion. (With J. T. Dorrance.) Ber. 
der dents, chem. Gesellschaft, 1895, 
Vol. 28, pp. 2349-2352. Translation 
in Jour. Am. Chem. Soc, 1895, Vol. 
17, pp. 855-859. 

The Occurrence of Trimethylene Glycol as 
a By-product in the Glycerine Manu- 
facture. (With W. H. Watkins.) 
Jour. Am. Chem. Soc, 1895, Vol. 
17, pp. 890-891. Also Technology 
Quarterly, 1895, Vol. 8, pp. 261- 
262. 

Die katalytische Wirkung der Wasser- 
stoffjonen auf polymolekulare Eeak- 
tionen. Zeits. f. physik. Chemie, 
1896, Vol. 19, pp. 599-606. 

Bemerkung iiber das Gesetz der Ge- 
schwindigkeit der Reaktion zwischen 
Eisenchlorid und Zinnchlorur. Ibid., 

1896, Vol. 21, p. 16. 

Die innere Eeibung des Quecksilber- 
dampfes. (With H. M. Goodwin.) 
Ibid., 1896, Vol. 21, pp. 671-679. 
Translation in Physical Beview, Nov.- 
Dec, 1896, Vol. 4, pp. 207-216. 

Sind Diphenyljodonium- und Thallium- 
nitrat isomorph? (With C. W. Hap- 
good. Zeits. f. physik. Chemie, 1896, 
Vol. 22, pp. 464^65. 

Instruction in Theoretical Chemistry. 
Technology Quarterly, 1896, Vol. 9, 
pp. 323-325. 

Formation of Diacetylenyl (Butadiine) 
from Copper Acetylene. (With C. 
W. Tucker.) Am. Chem. Jour., Feb. 

1897, Vol. 19, pp. 123-128. 
Synthesis of Hexamethylene-Glycol Di- 
ethyl Ether and Other Ethers from 



Trimethylene Glycol. Ibid., Nov., 

1897, Vol. 19, pp. 766-781. 
Die Reaktionsgesohwindigkeit zwischen 

Eisenchlorur, Kaliumchlorat und Salz- 

saure. (With R. S. Wason.) Zeits. 

f. physik. Chemie, 1897, Vol. 22, pp. 

210-221. Translation in Jour. Am. 

Chem. Soc, 1897, Vol. 19, pp. 199- 

213. 
Bestimmung des osmotisohen Druckes mit- 

tels Dampfdruckmessungen. (With C. 

G. Abbot.) Zeits. f. physik. Chemie, 

1897, Vol. 23, pp. 56-77. 
Ueber die Aufiosungsgeschwindigkeit von 

festen Stoffen in ihren eigenen Lo- 

sungeu. (With W. R. Whitney.) 

Ibid., pp. 689-692. Translation in 

Jour. Am. Chem. Soc, 1897, Vol. 19, 

pp. 930-934. 
Bemerkung tlber die Kinetische Theorie 

derLosungen. Zeits. f. physik. Chemie, 

1897, Vol. 24, p. 366. 
Qualitative Chemical Analysis. The Mac- 

millan Co., N. Y., 1897. 89 pp. 

Third edition. 
Laboratory Experiments on the Class 

Reactions and Identiiication of Organic 

Substances. (With S. P. Mulliken.) 

Chemical Publishing Co., Easton, Pa., 

1897. 31 pp. Second edition. 
Investigation of the Theory of Solubility 

Effect in the case of Trionic Salts. 
(With E. H. Woodworth.) Jour. Am. 
Chem. Soc, 1898, Vol. 20, pp. 194- 
201. Also Zeits. f. physik. Chemie, 

1898, Vol. 26, pp. 152-158. 

The Reliability of the Dissociation Values 
Determined by Electrical Conductivity 
Measurements. Jour. Am. Chem. 
Soc, 1898, Vol. 20, pp. 517-528. Also 
Zeits. f. physik. Chemie, 1898, Vol. 
26, pp. 699-710. 

The Solubility of Salts of Weak Acids 
in Stronger Acids. (With David 
Schwartz.) Jour. Am. Chem. Soc, 
1898, Vol. 20, pp. 743-751. Also Zeits. 
f. physik. Chemie, 1898, Vol. 27, pp. 
279-284. 

Die Theorie der Losliohkeitsbeeinflussung 
bei zweiioningen Eleotrolyten mit 
lauter verschiedenen Jonen. Zeits. 



Published Papers. 



535 



/. physik. Chemie, 1898, "Vol. 27, pp. 

267-278. 
The Solubility of Acids in Solutions of the 

Salts of Other Acids. (With E. S. 

Chapia.) 7 Wd. , pp. 442-446. Trans- 
lation in Jour. Am. Chem. Soc, 1898, 

Vol. 20, pp. 751-756. 
Die Loslichkeit von Jod in verdiinnten 

Kaliumjodidlosungen. (With L. J. 

Seidensticker.) Zeits. f. physik. 

Chemie, 1898, Vol. 27, pp. 357-360. 

Translation in J"o?«?'. Am. Chem. Soc, 

1899, Vol. 21, pp. 217-220. 
Die Geschwindigkeit der Reaktion zwischen 

Silberaoetat imd Natriumformiat. 

Eine Reaktion dritter Ordnung. (With 

G.T.Cottle.) Zeits. f. physik. Chemie, 

1898, Vol. 27, pp. 579-584. 

Die Beziehung zwischen osmotischer Ar- 
beit und osmotischem Druck. Ibid., 

1899, Vol. 28, pp. 220-224. 

C. A. ORR; — 

A.B., University of Michigan, 1887 ; Stu- 
dent, Johns Hopkins University, 1887-88 ; 
Principal, High School, Salem, O., 1888- 
89 ; Anthropologist, Solar Sclipse 
Expedition, Clark University, 1889- 
90 ; Lecturer in Latin, University of 
Chicago, 1892- ; Instructor, Chicago High 
Schools, 1894-. 

VICTOR PAPCKE: — 

Ph.D., University of Gottingen, 1888; 
Assistant in Cbemistiy, Clark Univer- 
sity, 1889-90; Medical Student, Uni- 
versity of Leipzig, 1893. 

GEORGE E. PARTRIDGE: — 

Special Student in Philosophy, Clark 
University, 1895-96 ; Scholar in Psy- 
chology, 1896-98 ; Fellow, 1898-99. 

Author of : — 

Second Breath. Pedagogical Seminary, 

April, 1897, Vol. 4, pp. 372-381. 
Blushing. lUd., April, 1897, Vol. 4, pp. 

387-394. 
Some Mental Automatisms. (With E. H. 

Liudley.) Ibid., July, 1897, Vol. 5, 

pp. 41-60. 



Reverie. Ibid., April, 1898, Vol. 5, pp. 
445-474. 

Child Study in Connection with the Va- 
cation Schools. (With H. S. Curtis.) 
Report on the Vacation Schools and 
Playgrounds, N. Y. City, Borough of 
Manhattan and the Bronx, 1898, pp. 
51-97. 

Experiments upon the Control of the 
Reflex. Am. Jour, of Psy. (In 
press.) 

T. RICHARD PEEDE: — 

Christian Biblical Institute, New York, 
1881-84 ; Boston University, 1884-85 ; 
Special Student in Philosophy and 
Pedagogy, Clark University, 1895-96 ; 
Honorary Scholar in Philosophy, 
1896-97 ; Pastor, South Baptist Church, 
Worcester, 1895-. 

JOSEPH DE PEROTT:— 

Universities of Paris and Berlin, 1877-80 ; 
Decent in Mathematics, Clark Uni- 
versity, 1890-. 

Author of: — 

Sur la sommation des nombres. Bull, des 

Sci. Mathematiques, 1881, 2d ser. , Vol. 

5, pp. 37-40. 
Sur 1' infinite de la suite des nombres pre- 
miers. Ibid., pp. 183-184. 
Sur une arithm^tique espagnole du 16™<^ 

si6cle. Bull, di bibliografia e di storia 

delle scienze matematiche, 1882, Vol. 

15, pp. 163-170. 
Sur la recherche des diviseurs des fonc- 

tions entiferes. Bull, de la Soc. Mathe- 

matique, 1882, Vol. 10, pp. 250-251. 
Sur un th^or^me de Gauss. Ibid. , pp. 87- 

88. 
Sur la formation des determinants irr^gu- 

liers. Jour. f. Mathematik, 1883, 

Vol. 95, pp. 232-237. 
Sur le probl6me des fous. Bull, de la Soc. 

Mathematique, 1883, Vol. 11, pp. 173- 

186. 
Sur la formation des dfterminants irr^gu- 

liers. Second M^moire. Jour. f. 

Mathematik, 1884, Vol. 96, pp. 327- 

348. 



536 



Titles of 



Demonstration du th^orfeme fondamental 
de I'algfebre. Ihid., 1885, Vol. 99, pp. 
141-160. 

Demonstration de I'existenoe des raoines 
primitives pour les modules ^gaux ci 
des puissances de nombre premier im- 
pair. Bull, des Sci. Mathematiques, 
1885, 2= s(§r., Vol. 9, pp. 21-24. 

Sur les logarithmes ^ un grand nombre de 
d^cimales et en particulier sur les Ta- 
bles de Steinhauser. Ihid., 1887, 2= 
sf^r.. Vol. 11, pp. 51-60. 

Sur I'^quation J 2 — Z)m 2 = — 1. Jour. 
f. Mathematik, 1888, Vol. 102, pp. 185- 
223. 

Remarque au sujet du tbeor^me d'Euolide 
sur I'infinite du nombre des nombres 
premiers. Am. Jour, of Mathematics , 
1888, Vol. 11, pp. 99-138 ; 1891, Vol. 
12, pp. 235-308. 

Sur une proposition empirique enono^e au 
Bulletin. Bull, de la Soc. 3Iathema- 
tique, 1889, Vol. 17, pp. 15-5-156. 

On a Theorem of Gauss. J. H. U. Circu- 
lar, 1889, No. 78, p. 30. 

The Gaussian Interpolation Theory, for- 
mulse for n = 7, 8, 9. Quar. Jour, of 
Mathematics, 1891, Vol. 25, pp. 200- 
202. 

Sur les groupes de Galois. Bull, de la 
Soc. Mathematique, 1893, Vol. 21, pp. 
61-65. 

Demonstration de I'existence de racines 
primitives pour tout module premier 
impair. Bull, des Sci. Mathematiques, 
1893, 2= ser., Vol. 17, pp. 66-83. 

Demonstration de I'existence de racines 
primitives module premier impair. 
Ibid., 1894, 2' ser., Vol. 18, pp. 64-66. 

Mathematical Tables. Sci. Am. Supple- 
ment, July 7, 1894, Vol. 38, pp. 15436- 
15437. 

The Theory of Numbers. (Review of M. 
Stieltjes's "Sur la theorie des nom- 
bres.") Bull, of Am. Math. Soc, 
June, 1895, Vol. 1, pp. 217-232. 

DANIEL EDWARD PHILLIPS: — 

Graduate West Virginia State Normal 
School, 1890 ; Principal, Public Schools, 
Philippi, W. Va., 1890-91; A.B., Uni- 



versity of Nashville, 1893 ; A.M., ibid., 
1894 ; Scholar in Psychology, Clark 
University, 1894- March, 1895 ; Pro- 
fessor of Pedagogy, Normal Department, 
University of Georgia, March, 1895-Jan., 
1897 ; Honorary Scholar in Psychol- 
ogy, Clark University, Jan.-Jime, 
1897; Fellow, 1897-98; Ph.D., 
Clark University, 1898 ; Professor of 
Philosophy and Education, University of 
Denver, 1898-. 

Author of : — 

The End of Education. 22 pp. 

Religious Education. Peabody Becord, 
Nov., 1893, Vol. 4, pp. 5.3-60. 

Courses of Study for Common Schools. 
Southern Jour, of Ed., Oct., 1896, Vol. 
9, pp. 472-478. 

Genesis of Number Forms. Am. Jour, of 
Fsy., July, 1897, Vol. 8, pp. 506-527. 

Number and its Application psychologi- 
cally considered. Pedagogical Sem- 
inary, Oct., 1897, Vol. 5, pp. 221-282. 

Some Remarks on Number and its Appli- 
cation. Ibid., April, 1898, Vol. 5, pp. 
590-599. 

Some Aspects of the Child Study Move- 
ment. Northwestern 3Ionthly, Jan., 
1899, Vol. 9, pp. 233-237. 

The Teaching Instinct. Pedagogical Sem- 
inary, March, 1899, Vol. 6, pp. 188- 
246. 

Sunday-School Teaching. Study, March, 
1899, Vol. 4, pp. 309-313. 

JEFFERSON R. POTTER:— 

A.B., Brown University, 1877 ; A.M., 
ibid., 1887; Instructor, Vermont Academy, 
1877-78 ; State Normal School, Castine, 
Me., 1878-85; Professor of Pedagogy, 
State College of Kentucky, 1885-88 ; In- 
structor in Natural Sciences, State Nor- 
mal School, Earmington, Me., 1888-90; 
Scholar in Psychology, Clark Uni- 
versity, 1890-91 ; Superintendent of 
Schools, Ashland and Hopkinton, Mass., 
1891-92 ; Superintendent of Schools, Wal- 
pole, Eoxboro, and Norfolk, Mass., 1892- 
95 ; Superintendent of Schools, Walpole 
and Eoxboro, Mass., 1895-98 ; Member : 



Published Papers. 



537 



New England Conference of Educational 
Workers ; New England Association of 
School Superintendents. 

Author of : — 

History of Methods of Instruction in 
Geography. Pedagogical Seminary, 
Dec, 1891, Vol. 1, pp. 415-424. 

J. O. QUANTZ: — 

B.A., University of Toronto (Honors in 
Philosophy and Psychology), 1894 ; Fel- 
low in Psychology, University of Wiscon- 
sin, 1895-97 ; Ph.D., University of Wis- 
consin, 1897 ; Honorary Fellovr in Psy- 
chology, Clark University, 1897-98 ; 
Honorary Fellow in Philosophy, Cornell 
University, 1898-99. 

Author of: — 

The Influence of the Color of Surfaces on 
our Estimation of their Magnitude. 
Am. Jour, of Psy., Oct., 1895, Vol. 7, 
pp. 26-41. 

Problems in the Psychology of Reading. 
Psychological Beview, Monograph Sup- 
plement, Dec, 1897, pp. 1-51. 

The Physiology of Shorthand. Phono- 
graphic World, March, 1898, Vol. 13, 
pp. 292-293. 

Dendro-psychoses. Am. Jour, of Psy., 
July, 1898, Vol. 9, pp. 449-506. 

An Analysis of the Muscular Sensations 
involved in Drawing a Line. 

ROLLA R. RAMSirST: — 

Assistant in Shop, Indiana University, 
1894-95; A.B., Department of Physics, 
ibid., 1895; A.M., ibid., 1898; Science 
Teacher, Decatur, Ind., High School, 
1895-96 ; Laboratory Assistant, Indiana 
University, 1896-97 ; Professor of Physios, 
Westminster College, 1897-98 ; Scholar 
in Physics, Clark University, 1898- 
99 ; Assistant in Physios, Cornell Univer- 
sity, 1899-. 

Author of : • — 

A Photographic Study of Electrolytic 
Cells. Physical Beview, Sept., 1899, 
Vol. 9, pp. 189-190, 1 pi. 



JOHN F. REIGAHT: — 

A.B., Dickinson College, 1888 ; Principal 
of High School, Chester, Pa., 1888-90; 
Scholar in Psychology, Clark Univer- 
sity, 1890-91 ; Associate Professor in 
Education, Teachers' College, New York 
City, 1891-92; Professor of Psychology 
and History of Education, ibid. , 1892-97 ; 
Superintendent Workingman's School, 
New York City, 1897-. 

Author of : — 

The Training of Teachers in England. 
Pedagogical Seminary, Dec, 1891, 
Vol. 1, pp. 409-415. 

ERNEST W. RETTGER: — 

Graduate, Indiana State Normal School; 
1891 ; A.B., Indiana University, 1893 ; 
Principal, Rensselaer, Ind., High School, 
1893-94 ; Instructor in Mathematics, Indi- 
ana University, 1894-95 ; Fellow in 
Mathematics, Clark University, 1895- 
98; Ph.D., Clark University, 1898; 
Instructor in Mathematics, Indiana Uni- 
versity, 1898-. 

Author of : — 

Note on the Projective Group. Proc. Am. 

Acad, of Sci., July, 1898, Vol. 38, pp. 

491-499. 
On Lie's Theory of Continuous Groups. 

Am. Jour, of Math. (In press.) 

ROBERT J. RICHARDSON :- 

Teacher in Public Schools, Varna, Ont., 
1887-90 ; Graduate, Ontario School of 
Pedagogy, 1891; Student at Toronto Uni- 
versity, 1892-93 ; Teacher in High School, 
Presoott, Ont., 1893-94 ; B.A., University 
of Toronto, 1897 ; Graduate Student, 
ibid., 1897-98 ; Fellow in Psychology, 
Clark University, 1898-99. 

Author of : — 

A case of Abnormal Color-Sense exam- 
ined with Special Reference to the 
Space-Threshold of Colors. (With J. 
W. Baird.) Univ. of Toronto Studies, 
Psychological Series, 1898, pp. 87- 
100. 



538 



Titles of 



CAMILLE RIBD: — 

Protestant School, Freiburg, Baden, 1850- 
52 ; Classical Gymnasium, Latir, Baden, 
1852-60 ; Student in Paris, 1862-63 ; Resi- 
dent in Paris, 1862-65, and 1867-70 ; 
Resident in Spain, 1865-67 ; Student in 
Freiburg, 1870-71 ; Student in Boston, 
1881-86 ; Head of School of Languages, 
Boston, 1887-90 ; Instructor in Modern 
Languages, Clark University, 1889- 
91 ; Instructor, Nautical School, U. S. S. 
Enterprise, 1891-94. 

STANLEY H. ROOD : — 

S.B., Worcester Polytechnic, in Mechan- 
ical Engineering, 1890 ; in Electrical En- 
gineering, 1891 ; Instructor in Physios, 
ibid., 1890-93; Scholar in Physics, 
Clark University, Sept., 1893- April, 
1894 ; Instructor in Joinery, Mechanic 
Arts High School, Boston, April-June, 
1894; Instructor in French, ihid., 1894- 
96 ; Graduate Student, Harvard Univer- 
sity, 1895-96 ; Instructor in Joinery, 
Manual Training High School, Worcester, 
1896-. 

ERWIN -W. RUNKLE: — 

A.B., Western College, 1890; Graduate 
Student in Psychology and Philosophy, 
Yale University, 1890-93 ; Lecturer in the 
History of Philosophy, ibid., 1892-93; 
Ph.D., Yale University, 1893; Assistant 
Professor of Psychology and Ethics, Penn- 
sylvania State College, 1893-99 ; Honor- 
ary Fellow in Psychology, Clark 
University, Jan.-June, 1899 ; Professor 
of Psychology and Ethics, Pennsylvania 
State College, 1899-. 

Author of : — 

Education and Life. Free Lance, State 

College, Pennsylvania, Jan., 1894, Vol. 

13, pp. 96-98. 
Why do we Dream? 75iU, Oct. 1895, 

Vol. 14, pp. 5-8. 
Factors in Education. Ibid., May, 1896, 

Vol. 15, pp. 12-18. 
Psychology and the Modem Novel. School 

Gazette, June, 1897, Vol. 8, pp. 8-12. 
Review of Breuer and Freud : Studien 



tlber Hysterie. Am. Jour, of Psy., 
July, 1899, Vol. 10, pp. 592-594. 

S. EDVTARD RYERSON: — 

M.A., Queen's University, 1895 ; FeUow 
in Mathematics, Clark University, 
1895-96. 

Died, March 25, 1896. 

EDMUND C. SANFORD: — 

A.B., University of California, 1883; 
Teacher in Oahu College, Hawaiian Is- 
lands, 1883-85 ; Student, Johns Hopkins 
University, 1885-88 ; University Scholar, 
ibid., 1887 ; Fellow, ibid., 1887-88 ; Ph.D., 
Johns Hopkins University; 1888 ; Instruc- 
tor in Psychology, ibid., 1888-89 ; Instruc- 
tor in Psychology, Clark University, 
1889-92 ; Assistant Professor of Psy- 
chology, 1892- ; Joint Editor, with 
President Hall and Professor Titohener, 
of the American Journal of Psychology ; 
Member of the American Psychological 
Association. 

Author of : — 

The Writings of Laura Bridgman. (Two 
articles.) Overland Monthly, 1886-87. 

The Relative Legibility of the Small 
Letters. Am. Jour, of Psy., May, 
1888, Vol. 1, pp. 402-435. 

Personal Equation. Ibid., Nov., 1888; 
Feb. and May, 1889, Vol. 2, pp. 3-38, 
271-298, 403-430. 

A Simple and Inexpensive Chronoscope. 
Ibid., April, 1890, Vol. 3, pp. 174-181. 

Psychology at Clark University. Ibid., 
April, 1890, Vol. 3, pp. 284-285. 

A Laboratory Course in Physiological 
Psychology. Ibid., April and Dec, 
1891 ; April, 1892, Vol. 4, pp. 141- 
155, 303-322, 474-490; April, 1893, 
Vol. 5, pp. 390-415; Jan., 1895, Vol. 
6, pp. 593-616; April, 1896, Vol. 7, 
pp. 412-424. 

A New Visual Illusion. Science, Feb. 17, 
1893, Vol. 21, pp. 92-93. 

On Reaction-Times when the Stimulus is 
Applied to the Reacting Hand. (With 
J. F. Reigart.) Am. Jour, of Psy., 
April, 1893, Vol. 5, pp. 351-355. 



Published Papers. 



539 



A New Pendulum Chronograph. Ibid., 
April, 1893, Vol. 5, pp. 385-389. 

Some Practical Suggestions on the Equip- 
ment- of a Psychological Laboratory. 
Ibid., July, 1893, Vol. 5, pp. 429-438. 

Notes on New Apparatus. Ibid., Jan., 
1895, Vol. 6, pp. 575-584. 

The Philadelphia Meeting of the American 
Psychological Association. Science, 
Jan. 24, 1896, Vol. 3, pp. 119-124. 

The Vernier Chronoscope. Am. Jour, of 
Psy., Jan., 1898, Vol. 9, pp. 191-197. 

A Course in Experimental Psychology. 
D. C. Heath & Co., Boston, Mass., 
1898. 449 pp. 

CLARENCE ARTHUR SAUNDERS: 
B.A., King's College, Windsor, N. S., 
1885; M.A., 1888; Graduate Student, 
Johns Hopkins University, 1889-92 ; Assis- 
tant, Smithsonian Institution, Washing- 
ton, 1891-92 ; Fellow in Physics, Clark 
University, 1892-95 ; Ph.D., Clark 
University, 189S ; Professor of Mathe- 
matics and Physics, Ursinus College, 
1895-98. 
Died Dec. 19, 1898. 

Author of : — 

The Velocity of Electric Waves. Physical 
Eeview, Sept. -Oct., 1896, Vol. 4, pp. 
81-105. 

ALBERT SCHINZ:— 

B.A., Neuohatel, 1888; M.A., ibid., 
1889 ; Licentiate in Theology, ibid., 1892 ; 
Student, University of Berlin, 1892-93; 
Student, Tubingen, 1893 ; Ph.D., Tiibin- 
gen, 1894 ; College de Prance et Sor- 
bonne, Paris, 1894 ; Second Librarian, 
Library of NeuchStel, and Associate Pro- 
fessor of Philosophy, University of Neu- 
ohatel, 1896-97 ; Honorary Fellow in 
Psychology, Clark University, 1897- 
98 ; Instructor in Prench, University of 
Minnesota, 1898-99 ; Lecturer in French 
Literature, Bryn Mawr College, 1899-. 

Author of : — 

La nature du p6ch6 : 6tude psychologique. 
Delachaux et Niestl^, Neuohatel, 1892. 
134 pp. 



Morale et d^terminisme. Revue Philoso- 
phique, Jan., 1895, Vol. 39, pp. 57-75. 

La philosophie de M. Ernest Naville. Be- 
vue de Theologie et de Philosophie, 
July, 1895. 

Mystioisme et Magie. Centralblatt des 
Zofingervereins, Dec, 1895. 

Le recent mouvement moral en Europe et 
en Amerique. Bridel et Cie, Lau- 
sanne, Suisse. (Imprim6 d'abord dans 
La Revue de Theologie et de Philoso- 
phie, Sept., 1896.) 

Essai sur la notion du miracle, consid^r^ 
du point de vue de la th^orie de la 
connaissance. Delachaux et Niestl^, 
Neuohatel, 1897. 35 pp. (Reprint 
from La Revue de Theologie et de Phi- 
losophie, March, 1897.) 

La morality de I'enfant. Revue Philoso- 
phique, March, 1898, Vol. 45, pp. 259- 
295. 

Die Moralitat des Kindes. Translation 
by Ch. Ufer. Langensalza, 1898. 42 
pp. (Heft I. der "Beitrage zur Kin- 
derf orschung. " ) ' 

Le positivisme est un m^thode et non un 
syst^me. Revue Philosophique, Jan., 
1899, Vol. 47, pp. 63-75. 

Les bibliothfeques publiques en Amerique. 
Bibliotheque Universelle, Lausanne, 
Suisse, Aug.-Sept., 1898. 

Les sports dans les Universit^s Am^ri- 
caines. La Suisse Universitaire, Feb. , 
1899. 

L'Universit^ de Clark k Worcester, Mass. 
Revue des Revues, Paris, July, 1898. 

L'^glise auxEtatsUnis d' Amerique. (In 
press.) 

Translation of Dr. E. C. Sanford's "A 
Course in Experimental Psychology," 
Schleicher frferes, Paris, 1899. (In 
press.) 

Chronique du f^minisme aux Etats-Unis. 
Revue de Morale Sociale, Paris, June, 
1898. 

La langue Internationale Esperanto. La 
Semaine Litteraire. Genfeve, Suisse, 
29 Juillet, 1899. 

La secte des Soientistes Chretiens aux 
Etats-Unis d' Amerique. Revue des 
Revues, Paris. (In press.) 



540 



Titles of 



Un repr^sentant de PAgnostioisme aiix 
Etats-Unis, Robert G. Ingersoll. (In 
press.) 

L'^ducation des nfegres aux Etats-Unis 
d'Amerique. L'institut de Tuskegee 
en Alabama. La Semaine Litteraire. 
Genfeye. 21 Ootobre, 1899. 

Le oulte d'Omar Khayyam. (In press.) 

La Philosophie et le Sens Commun, Be- 
vue Philosophique, Furis. (In press.) 

ALVA ROY SCOTT: — 

A.B., De Pauw University, 1886 ; A.M., 
ibid., 1889; Principal, Leavenworth 
Schools, 1886-87 ; Student, McCormick 
Theological Seminary, Chicago, 1888-91 ; 
Pastor, Eirst Presbyterian Church, 
Hanover, 111., 1891-93; Graduate Stu- 
dent, Harvard University, 1893-94 ; Hon- 
orary Scholar in Psychology, Clark 
University, 1894-95 ; Pastor, First 
Presbyterian Church, Worcester, Mass., 
1894-98. 

COLIN ALEXANDER SCOTT: — 

Student, College of City of New York, 
1877-78 ; Graduate, Toronto Normal 
School, 1879 ; Director of Instruction in 
Drawing, Kingston Schools, 1883-84 ; 
B.A., Queen's University, Kingston, 
Ont., 1885 (Gold Medalist with Honors 
in Chemistry, Biology, and Geology) ; In- 
structor in Chemistry, Ladies' Medical 
College, Kingston, 1885-86 ; Science Mas- 
ter, Ingersoll Collegiate Institute, 1886-87 ; 
Science Master, Ottawa Collegiate Insti- 
tute, 1887-94 ; Fellow in Psychology, 
Clark University, 1894-96 ; Ph.D., 
Clark University, 1896 ; Head of De- 
partment of Physiological Psychology and 
Child Study, Chicago Normal School, 
1896-. 

Author of : — 

Sex and Art. Am. Jour, of Psy., Jan., 
1896, Vol. 7, pp. 153-226. 

Old Age and Death. Ibid., June, 1896, 
Vol. 8, pp. 67-122. 

Children's Fears as Material for Expres- 
sion and a Basis of Education in Art. 
Trans. III. Soc. for Child Study, April, 
1898, Vol. 3, pp. 12-17. 



E. "W. SCRIPTURE: — 

A.B., College of the City of New York, 
1884; A.M., ibid., 1890; Universities of 
Leipzig, Berlin, and Zurich, 1888-90 ; 
Ph.D., University of Leipzig, 1891 ; Fel- 
low in Psychology, Clark University, 
1891-92 ; Instructor in Experimental 
Psychology, Yale University, 1892-98 ; 
Director of the Yale Psychological Labor- 
atory, 1898- ; Assistant Editor of Ameri- 
can Journal of Psychology, 1891-92 ; Edi- 
tor of Studies from the Yale Psychological 
Laboratory, 1893- ; Member : American 
Psychological Association ; American So- 
ciety of Naturalists ; Fellow, American 
Association for the Advancement of 
Science. 

Author of : — 

Vorstellung und Gefiihl. Philos. Studien, 
1890, Vol. 6, pp. 536-542. 

Ueber den associativen Verlauf der Vor- 
stellungen. (Inaugural Dissertation.) 
Leipzig, 1891, 101 pp., and Philos. Stu- 
dien, 1891, Vol. 7, pp. 50-146. 

Arithmetical Prodigies. Am. Jour, of 
Psy., April, 1891, Vol. 4, pp. 1-59. 

The Problem of Psychology. Mind, 1891, 
Vol. 16, pp. 30.5-326. 

Zur Definition einer Vorstellung. Philos. 
Studien, 1891, Vol. 7, pp. 213-221. 

Einige Beobachtungen tiber Schwebungen 
und Differenztone. Ibid., 1892, Vol. 
7, pp. 630-632. 

The Need of Psychological Training. Sci- 
ence, March 4, 1892, Vol. 19, pp. 127- 
128. 

An Instrument for Mapping Hot and Cold 
Spots on the Skin. Ibid. , May 6, 1892, 
Vol. 19, p. 258. 

Education as a Science. Pedagogical Sem- 
inary, June, 1892, Vol. 2, pp. 111- 
114. 

Psychological Notes. Am. Jour, of Psy., 
Aug., 1892, Vol. 4, pp. 577-584. 

Tests on School Children. Educational 
Sevieio, Jan., 1893, Vol. 5, pp. 52- 
61. 

1st eine oerebrale Entstehung von Schwe- 
bungen moglioh ? Philos. Studien, 
1893, Vol. 8, pp. 638-640. 



Published Paper's. 



541 



Systematized Graduate Instruction in Psy- 
chology. Science, July 28, 1893, Vol. 
12, pp. 43-44. 

A System of Color-teaching. Educational 
Meview, Dec, 1893, Vol. 5, pp. 464-474. 

Consciousness under the Influence of Can- 
nabis indica. Science, Oct. 27, 1893, 
Vol. 22, p. 233. 

Psychological Measurements. Philosophi- 
cal Beview, Nov. 1893, Vol. 2, pp. 
677-689. 

A New Reaction-key and the Time of 
Voluntary Movement. (With J. M. 
Moore.) Studies from Yale Psy. 
Lab., 1892-93, Vol. 1, pp. 88-91. 

Drawing a Straight Line : a Study in 
Experimental Didactics. (With C. I. 
Lyman.) Ibid., pp. 92-96. 

Some New Psychological Apparatus. Ibid., 
pp. 97-100. 

On the Measurement of Hallucinations. 
Science, Dec. 29, 1893, VoL 22, p. 353. 

Work at the Yale Laboratory. Psycho- 
logical Beview, Jan., 1894, Vol. 1, pp. 
66-69. 

TJeber die Aenderungsempfindlichkeit. 
Zeits. f. Psy. u. Phys. d. Sinnesorgane, 
1894, Vol. 6, pp. 472-474. 

Observation on the Use of the Terminal 
Verb in Infant Speech. Science, Feb. 
2, 1894, Vol. 23, p. 62. 

New Materials for Color- teaching. Edu- 
cational Bevieio, April, 1894, Vol. 7, 
pp. 382-383. 

The Use of Antiphones. iV. T. Med. Jour., 
April 7, 1894, Vol. 59, p. 43. 

On the Adjustment of Simple Psychologi- 
cal Measurements. Psychological Be- 
view, May, 1894, Vol. 1, pp. 281-282. 

The Kinesimeter. (With E. B. Titchener.) 
Am. Jour, of Psy., June, 1894, Vol.6, 
pp. 424-426. 

Accurate Work in Psychology. Ibid., 
pp. 427-430. 

Some Psychological Illustrations of the 
Theorems of Bernoulli and Poisson. 
Ibid., pp. 431-432. 

Methods of Laboratory Mind-study. Fo- 
rum, Aug., 1894, Vol. 17, pp. 721- 
728. 

Aims and Status of Child Study. Educa- 



tional Beview, Oct., 1894, Vol. 8, pp. 

236-239. 
On Mean Values for Direct Measurements. 

Studies from Tale Psy. Lab., 1894, 

Vol. 2, pp. 1-39. 
Remarks on Dr. Gilbert's Article. Ibid., 

pp. 101-104. 
Experiments on the Highest Audible Tone. 

(With H. F. Smith.) Ibid., pp. 105- 

113. 
On the Education of Muscular Control and 

Power. (With T. L. Smith and E. M. 

Brown.) Ibid., pp. 114-119. 
A Psychological Method of determining 

the Blind-spot. /6jU, pp. 120-121. 
Tests of Mental Ability as Exhibited in 

Fencing. Ibid., pp. 122-124. 
Eeaction-time and Time-memory in Gym- 
nastic Work. Bep. Ninth Meet. Am. 

Ass^n Physical Education, 1894, pp. 

44-49. 
On the Measurement of Imaginations, 

Sci. Am., Feb. 9, 1895, Vol. 72, p. 

85. 
The Nature of Science and Its Relation to 

Philosophy. Science, March 29, 1895, 

N. S., Vol. 1, pp. 350-352. 
Scientific Child Study. Trans. III. Soc. 

for Child Study, May, 1895, Vol. 1, 

pp. 32-37. 
Simple but Accurate Tests for Child Study. 

Ibid., pp. 57-60. 
Practical Computation of the Median. 

Psychological Beview, July, 1895, Vol. 

2, pp. 376-379. 
The Second Year at the Yale Laboratory. 

Ibid., pp. 379-381. 
A New Method of Computation.' Sci. 

Am. Supplement, July 6, 1895, Vol. 4, 

p. 16270. 
Thinking, Feeling, Doing. Flood & Vin- 
cent, Meadville, Pa., 1895. 304 pp. 
A New Method of Making Lantern Slides. 

Scientific American, Aug. 24, 1895, 

Vol. 73, p. 123. 
Some Principles of Mental Education. 

School Beview, Nov., 1895, Vol. 3, pp. 

533-547. 
A Method of Stereoscopic Projection. 

Scientific American, Nov. 23, 1895, 

Vol. 73, p. 327. 



542 



Titles of 



Some New Apparatus. Studies from 
Tale Fsy. Lab., 1895, Vol. 3, p. 98- 
109. 

The Bad Eye Factory. Outlook, Feb. 29, 

1896, Vol. 53, pp. 393-394. 
Untersuchimgen iiber die geistlge Ent- 

wickelung der Sohulkinder. Zeits. f. 

Psy. w. Phys. der Sinnesorgane, 1896, 

Vol. 10, pp. 161-182. 
Measuring Halluoinations. Science, May 

22, 1896, N. S., Vol. 3, pp. 762-763. 
Child Study : Methods and Results. Be- 

port 65th Meeting Am. Institute of 

Instruction, pp. 181-188. 
The Third Year at the Yale Laboratory. 

Psychological Revieio, July, 1896, Vol. 

3, pp. 416-421. 
The Law of Rhythmic Movement. Sci- 
ence, Oct. 9, 1896, N. S., Vol. 4, pp. 

535-536. 
My Pedagogic Creed. School Journal, 

Dec. 5, 1896, Vol. 53, pp. 621-623. 
Nouveaux Instruments. Annee psycholo- 

gique, 1896, Vol. 3, pp. 658-664. 
The Law of Size-Weight Suggestion. Sci- 
ence, Feb. 5, 1897, N. S., Vol. 5, p. 227. 
Sources of the New Psychology. Pop. Sci. 

Mo., May, 1897, Vol. 51, pp. 98-106. 
Pleasure without Other Sensations. N. T. 

Med. Jour., July 17, 1897, Vol. 66, p. 

99. 
Cerebral Light. Science, July 23, 1897, 

N. S., Vol. 6, pp. 138-139. 
The New Psychology. Walter Scott, Lon- 
don, 1897. 500 pp. 
Researches on Reaction-time. Studies 

from Tale Psy. Lab., 1897, Vol. 4, pp. 

12-26. 
Researches on Voluntary Effort. Ibid., 

1897, Vol. 4, PP.-69-75. 

New Apparatus and Methods. Ibid., 
1897, Vol. 4, pp. 76-88. 

Elementary Course in Psychological Meas- 
urements. Ibid., 1897, Vol. 4, pp. 89- 
139. 

On Binaural Space. Ibid., 1898, Vol. 5, 
pp. 76-80. 

Researches on the Memory for Arm 
Movements. (With W. C. Cooke and 
C. M. Warren.) Ibid., 1898, Vol. 5, 
pp. 90-92. 



Principles of Laboratory Economy. Ibid., 

1898, Vol. 5, pp. 93-103. 
Reaction-time in Abnormal Conditions 

of the Nervous System. Medical Bec- 

ord, 1898, Vol. 53, p. 196. 
Electrical Anaesthesia. Science, June 3, 

1898, N. S., Vol. 7, p. 776. 
The Anaesthetic Effects of a Sinusoidal 

Current of High Frequency. Ibid., 

March 10, 1899, N. S., Vol. 9, p. 377. 
Color Weakness and Color Blindness. 

Ibid., June 2, 1899, N. S., Vol. 9, pp. 

771-774. 
Cerebral Light. Ibid., June 16, 1899, 

N. S., Vol. 9, pp. 850-851. 
Arousal of Instinct by Taste. Ibid., June 

23, 1899, N. S., Vol. 9, p. 878. 
Anaglyphs and Stereoscopic Projection. 

Ibid., Aug. 11, 1899, N. S., Vol. 10, 

pp. 185-187. 

CHARLES H. SR&RS: — 

Graduate, State Normal School, Westiield, 
Mass. (four years' course), 1883 ; Princi- 
pal of Public Schools, Cheshire, Mass., 
1883-85; Teacher, Prospect Park Insti- 
tute, Brooklyn, N. Y., 1885-88; Teacher 
of Latin, State Normal School, Edinboro, 
Pa., 1888-92; A.M., Allegheny College, 
1893; Ph.D., Allegheny College, 1895; 
Principal, Normal Department, Claflin 
University, 1892-97 ; Honorary Fellow 
in Pedagogy, Clark University, 1897- 
99. 

Author of: — 

Home and School Punishments. Peda- 
gogical Seminary, March, 1899, Vol. 
6, pp. 159-187. 

ALBERT E. SEGSWORTH: — 

B.A., University of Toronto, 1890 ; Stu- 
dent, University of Leipzig, 1890-91 ; Uni- 
versity of Toronto, 1891-92 ; Student, 
University of Leipzig, 1892-93 ; Honor- 
ary Fellow in Psychology, Clark 
University, 1893-94. 

Author of : — 

On the Difierence Sensibility for the 
Valuation of Space Distances with the 
Help of Arm Movements. Am. Jour. 



Published Papers. 



hii 



of Psy., June, 1894, Vol. 6, pp. 369- 
407. 
Ueber Innervationsempflndungen. (Pri- 
vately printed. ) 1894. 5 pp. 

BENJAMIN F. SHARPB: — 

A.B., Wesleyan University, 1887; A.M., 
ibid., 1890; Adjunct Professor of Physios 
and Biology, Randolph-Macon College, 
1887-91 ; Graduate Student and Scholar, 
Johns Hopkins University, 1891-94 ; Fel- 
low in Physics, Clark University, 
1894-96 ; Professor of Mathematics, 
State Normal School, New Paltz, N. Y., 
1896-97 ; Fellow in Physics, Clark 
University, 1897-98. 

Author of: — 

A Double Instrument and a Double 
Method for the Measurement of 
Sound. Science, June 9, 1899, N. S., 
Vol. 9, pp. 808-811. 

An Advance in Measuring and Photo- 
graphing Sounds. U. S. Weather Bu- 
reau, No. 202, "Washington, D. C, 
1899. 18 pp., 7 pis. 

JOHN C. SHA-W: — 

Graduate, State Normal School, Fairmont, 
W. Va., 1889; Principal of Graded 
Schools, Paw Paw, W. Va., 1889-90; 
B.S., University of Nashville, 1892 ; M.S., 
ibid., 1894; L.I., Peabody Normal Col- 
lege, Nashville, 1893 ; Principal of Public 
School, Douglassville, Tex., 1893-94; 
Teacher of Mathematics, Marshall Col- 
lege, 1894-95; Scholar in Pedagogy, 
Clark University, 1895-96 ; Fellow 
in Psychology, 1896-97; Teacher in 
State Normal School, West Liberty, W. 
Va., 1897-. 

Author of : — 

Chairs of Pedagogy in the United States. 

W. Va. School Journal, April, May, 

and June, 1895. 
A Test of Memory in School Children. 

Pedagogical Seminary, Oct., 1896,Vol. 

4, pp. 61-78. 
What Children like to Read. W. Va. 

School Journal, Charleston, W. Va., 

Oct., 1897, Vol. 17, pp. .5-6. 



HENRY DAVIDSON SHELDON: — 

A.B., Stanford University, 1896; A.M., 
ibid., 1897 ; Instructor in Department of 
Education, ibid., 1896-97 ; Fellow and 
Assistant in Pedagogy, Clark Univer- 
sity, 1897-99. 

Author of : — 

The Institutional Activities of American 
Children. Am. Jour, of Psy., July, 
1898, Vol. 9, pp.- 425-448. 

FREDERIC D. SHERMAN: — 

A.B., University of Michigan, 1887 ; 
Principal of Berrien Springs, Mich., 
School, 1887-88; Principal of Charlotte, 
Mich., High School, 1888-89; Principal 
of Bay City, Mich., High School, 1889- 
94 ; Universities of Bonn and Leipzig, 
1894-97; Ph.D., University of Leipzig, 
1897 ; Professor of Psychology and Peda- 
gogy, State Normal School, Oshkosh, 
Wis., 1897-98; Honorary Fellow in 
Psychology, Clark University, Oct.- 
Nov. , 1898 ; Lecturer in History of Edu- 
cation, Teachers College, Columbia Uni- 
versity, Dec, 1898-June, 1899; Assistant 
in Latin, Erasmus Hall High School, 
Brooklyn, N. Y., 1899-. 

Author of: — 

Ueber das Purkinje'sche Phanomen im 
Centrum der Netzhaut. Philosophische 
Studien, 1897, Vol. 13, pp. 434-479. 

TOSHIHIDE SHINODA: — 

Graduate, Higher Normal School, Tokio, 
Japan ; Graduate Student in United States 
and Europe, 1888-91 ; Honorary Scholar 
in Pedagogy, Clark University, 1889- 
90 ; Professor in Higher Normal School, 
Tokio, Japan, 1891-. 

LOUIS SIPF: — 

S.B., Cornell University (Special Mention 
in Mathematics), 1897 ; Graduate Student, 
Johns Hopkins University, Oct., 1897- 
Feb., 1898; Scholar in Mathematics, 
Clark University, 1898-99 ; Teaching 
Fellow in Mathematics, University of Ne- 
braska, 1899-. 



544 



Titles of 



EHNEST B. SKINNER: — 

A.B., Ohio University, 1888 ; Professor 
of Mathematics, Amity College, College 
Springs, la., 1889-91 ; Scholar in Mathe- 
matics, Clark University, 1891-92 ; 
Instructor in Mathematics, University of 
Wisconsin, 1892-95 ; Assistant Professor, 
ibid., 1895- ; Member American Mathe- 
matical Society. 

STEPHEN E. SLOCUM : — 

B.E., Union University (Honors in Mathe- 
matics and Physics), 1897 ; Scholar 
in Mathematics, Clark University, 
1897-98; FeUow, 1898-99. 

Author of : — 

Note on the Chief Theorem of Lie's 
Theory of Continuous Groups. Proc. 
Am. Acad. (In press.) 

JAMES R. SLONAKBR : — 

Graduate, Indiana State Normal School, 
1889 ; Supervising Principal of Schools, 
Elroy, Wis., 1889-91 ; University of Wis- 
consin, 1891-93; B.S., ihid., 189.3; Fel- 
low in Biology, Clark University, 
1893-96 ; Ph.D., Clark University, 
1896 ; Instructor in Zoology, Indiana 
University, 1896- ; Member Indiana 
Academy of Science. 

Author of: — 

A Comparative Study of the Point of 

Acute Vision in the Vertebrates. 

American Naturalist, Jan., 1896, Vol. 

30, pp. 24-32. 
A Comparative Study of the Area of 

Acute Vision in Vertebrates. Jour. 

of Morph., May, 1897, Vol. 13, pp. 

445-502. 
The Fovea. Proc. Ind. Acad, of Science, 

1896, pp. 304-310. 
A Method of Preserving the Eye for 

Sectioning, or for Demonstrating the 

Area of Acute Vision. Jour, of 

Applied Microscopy, Feb., 1896, Vol. 

1, p. 18. 
The Eye of the Mammoth Cave Rat. 

Proc. Ind. Acad, of Science, 1898. 



MAURICE H. SMALL: — 

A.B., Colby University, 1887 ; Principal, 
High School, Norway, Me., 1887-92 ; 
ibid., Westbrook, Me., 1892-95 ; Scholar 
in Psychology, Clark University, 
1895-96 ; FeUow, 1896-98 ; Prin- 
cipal High School, Passaic, N. J., 1898-. 

Author of : — 

The Suggestibility of Children. Peda- 
gogical Seminary, Dec, 1896, Vol. 4, 
pp. 176-220. 

Methods of manifesting the Instinct for 
Certainty. Ibid., Jan., 1898, Vol. 5, 
pp. 313-380. 

An Experiment borrowed from the School- 
room. Northwestern Monthly, Nov., 
1898, Vol. 9, pp. 134-135. 

WILLARD STANTON SMALL: — 

A.B., Tufts College, 1894; A.M., ibid., 
1897 ; Tufts Divinity School, 1894-96 ; 
Professor of English Language and Lit- 
erature, Lombard University, 1896-97 ; 
Scholar in Psychology, Clark Uni- 
versity, 1897-98; Fellow, 1898-99. 

Author of : — 

Friedrich Nietzsche (Review). Pedagogi- 
cal Seminary, April, 1898, Vol. 5, 
pp. 606-610. 

Note on the Psychic Development of the 
Young White Rat. Am. Jour, of Psy., 
Oct., 1899, Vol. 11, pp. 80-100. 

WARREN R. SMITH: — 

A.B., Bowdoin College, 1890 ; Instructor 
Leicester Academy, Leicester, Mass., 
1890-91 ; Scholar in Chemistry, Clark 
University, 1891-92 ; Fellow in Chem- 
istry, University of Chicago, 1892-94 ; 
Ph.D., ibid., 1894 ; Assistant in Chemistry, 
Bowdoin College, 1894-95 ; Instructor in 
Science, New Bedford High School, 1895- 
96 ; Instructor in charge Department of 
Chemistry, Lewis Institute, Chicago, 111., 
1896-. 

Author of : — 

On the Addition Products of the Aro- 
matic Isooyanides. Am. Chem. Jour., 
May, 1894, Vol. 16, pp. 372-393. 



Published Papers. 



545 



HUGH A. SNEPP: — 

A.B., Heidelberg College, 1893 ; Princi- 
pal, High School, Germantown, O., 1893- 
94 ; Tutor in Mathematics, Heidelberg 
College, 1894-95 ; Scholar in Mathe- 
matics, Clark University, 1895-96 ; 
Instructor in Mathematics and Science, 
High School, Tiffin, O., 1896-98; Student 
in Mathematics, University of Chicago, 
Summer Quarter, 1897. 

FRANK E. SPAULDING-: — 

A.B., Amherst College, 1889; Instructor, 
Military Academy, Louisville^ Ky., 1889- 
90 ; Instructor and Associate Principal, 
ibid., 1890-91 ; Student in Universities of 
Leipzig, Paris, and Berlin, 1891-94 ; 
Ph.D., University of Leipzig, 1894 ; 
Honorary Fellow in Psychology, 
Clark University, Oct., 1894-May, 
1895 ; Superintendent of Schools, Ware, 
Mass., May, 1895- June, 1897; Superin- 
tendent of Schools, Passaic, N. J., Sep- 
tember, 1897- ; President, New Jersey 
Association for the Study of Children and 
Youth, 1899. 

Author of: — 

Richard Cumberland als Begrtinder der 
Englischen Ethik. Leipzig, 1894. xii. 
+ 101 pp. 

The Province of the Elementary School. 
Jour, of Pedagogy, Sept., 1896, Vol. 9, 
pp. 129-137. 

Mental Images. Educational Founda- 
tions, Sept., 1897, Vol. 9, pp. 15-21. 

The Dynamics of Mental Images. Ihid., 
Oct., 1897, Vol. 9, pp. 65-70. 

Some Psychic Processes involved in Read- 
ing. Ihid., Nov., 1897, Vol. 9, pp. 130- 
137. 

The Psychology of Defective Reading. 
Ihid., Dec, 1897, pp. 194-201. 

Mental Economy in Reading. /6id., Jan., 
1898, Vol. 9, pp. 257-262. 

Psychic Aspects of Learning to Read. 
Ihid., Feb., 1898, Vol 9, pp. 347- 
353. 

Preventing and Correcting Defective 
Reading. Ihid., March, 1898, Vol. 9, 
pp. 389-395. 
2n 



AVhat can One Read ? Ibid., April, 1898, 

Vol. 9, pp. 514-520. 
Psychology in Geography. Ihid., May 

and June, 1898, Vol. 9, pp. 572-577, 

619-625. 
The Elementary Character of Secondary 

Education. Jour, of Pedagogy, Jan., 

1899, Vol. 12, pp. 11-24. 
Immediate Educational Work. Anmial 

Report, Supt. of Schools, Ware, Mass., 

Feb. 1, 1896, pp. 17-22. 
Educational Policy and Aims. Ihid., Feb. 

1, 1897, pp. 14-32. 
The Course of Study ; Grading and Pro- 
motion, etc. Annual Beport, Supt. 

of Schools, Passaic, N. J., 1897-98, pp. 

9-64. 

EDWIN D. STARBUCK: — 

A.B., Indiana University, 1890 ; Teacher 
of Mathematics and Latin, Spiceland, 
Ind. Academy, 1890-91 ; Teacher of 
Mathematics, Vincennes College, 1891-93 ; 
Student in Psychology, Harvard Univer- 
sity, 1893-95; A.B., ibid. ; 1894; A.M., 
ibid., 1895; Fellovir in Psychology, 
Clark University, 1895-97 ; Ph.D., 
Clark University, 1897 ; Assistant Pro- 
fessor of Education, Stanford University, 
1897-. 

Author of : — 

A Study of Conversion. Am. Jour, of 
Psy., Jan., 1897, Vol. 8, pp. 268-308. 

Some Aspects of Religious Growth. Ihid. , 
Oct., 1897, Vol. 9, pp. 70-124. 

Child Study and its Possibility as a Sci- 
ence. Northwestern Monthly, March- 
April, 1899, Vol. 9, pp. 358-362. 

Psychology of Religion. With an intro- 
duction by Professor William James. 
Contemporary Science Series. (In 
press.) 

ORLANDO S. STETSON: — 

Worcester Polytechnic Institute, 1896-98 ; 
Scholar in Mathematics, Clark Uni- 
versity, 1898-99. 

COLIN C. STEWART: — 

B.A., University of Toronto, 1894; 
Scholar in Physiology, Clark Uni- 



546 



Titles of 



versity, 1894-95 ; FeUow, 1895-97 ; 
Ph. D., Clark University, 1897 ; As- 
sistant in Physiology, Harvard Medical 
School, 1897-98; Tutor in Physiology, 
Columhia University, 1898- ; Member 
American Physiological Society. 

Author of : — 

The Influence of Acute Alcohol Poisoning 
on Nerve Cells. Jour, of Exp. Medi- 
cine, Nov., 1896, Vol. 1, pp. 623-629. 

Variations in Daily Activity produced by 
Alcohol and by Changes in Barometric 
Pressure and Diet, with a Description 
of Recording Methods. Am. Jour, of 
Physiology, Jan., 1898, Vol. 1, pp. 40- 
56. 

On the Course of Impulses to and from 
the Cat's Bladder. Ihid., Jan., 1899, 
Vol. 2, pp. 182-202. 

A Simple Etherizing Bottle. Ihid. (Proc. 
Am. Physiol. Soc, Dec, 1898), Vol. 2, 
p. X. 

The Relaxation of the Cat's Bladder. 
Ihid., Aug., 1899, Vol. 3, pp. 1-8. 

JULIUS STIEGLITZ: — 

University of Berlin, 1886-89 ; University 
of Gottingen, 1888; Ph.D., University of 
Berlin, 1889; Scholar in Chemistry, 
Clark University, Jan.-Jvme, 1890 ; 
Chemist, Parke, Davis & Co., Detroit, 
Mich., 1890-92 ; Decent in Chemistry, 
University of Chicago, 1892-93 ; Assistant 
in Chemistry, ibid., 1893-94; Instructor 
in Chemistry, ihid., 1894-97 ; Assistant 
Professor in Chemistry, ihid., 1897- ; Fel- 
low of the American Association Advance- 
ment of Science; Member, Deutsche 
Chemisohe Gesellschaft. 

Author of : — 

Ueber das Verhalten der Amidoxime 

gegen Diazobenzolverbindungen. Ber. 

d. deuts. chem. Gesellschaft, 1889, Vol. 

22, pp. 3148-3160. 
On Benzoquinone Carboxylic Acids. Am. 

Chem. Jour., 1891, Vol. 13, pp. 38^2. 
Alkaloidwertbestimmung von Extrakten. 

Fharmaceutische Bundschau, 1892 and 

1893, 3 papers. 



Ferric Phosphate, XJ. S. P., and Ferric 
Pyrophosphate, U. S. P. Journal of 
Pharmacy, 1891. 

Notes on Pyrophosphorio and Phosphoric 
Acid. Ibid., 1891. 

Derivatives of Nitrogen Halogen Com- 
pounds. (With F. Lengfeld.) Am. 
Chem. Jour., 1893, Vol. 15, pp. 215- 
222, 504-518 ; Vol. 16, pp. 370-372. 

The Action of Phosphorus Pentachloride 
on Urethanes. (With F. Lengfeld.) 
Ibid., 1894, Vol. 16, pp. 70-78. 

Ueber Alkylisoharnstoffe. (WithF. Leng- 
feld.) Ber. d. deuts. chem. Gesell- 
schaft, 1894, Vol. 27, pp. 926-927. 

Ueber die Einwirkung von Natrium- 
athylat auf Carbodiphenylimid. Ibid., 
1895, Vol. 28, pp. 573-574. 

Ueber Thiamine. (With F. Lengfeld.) 
Ibid., 1895, Vol. 28, pp. 575-576, 2742- 
2744. 

On Imidoethers of Carbonic JUaid. (With 
F. Lengfeld.) Am. Chem. Jour., 1895, 
Vol. 17, pp. 98-113. 

On the "Beckmann Rearrangement." 
Ibid., 1896, Vol. 18, pp. 751-761. 

On the Constitution of the Salts of Imido- 
ethers and other Carbimide Deriva- 
tives. Ihid., 1899, Vol. 21, pp. 101- 
111. 

F. E. STINSON: — 

Iowa Agricultural College, 1884r-86 ; Prin- 
cipal, Poplar Grove Institute, Ark., 1889- 
90; Instructor in Physics and Mathematics, 
Paris Academy, Ark., 1890-92 ; Scholar 
in Mathematics, Clark University, 
1892-93 ; Fellovsr, 1893-95. 

■WILLIAM E. STOHY: — 

A.B., Harvard University, 1871 ; Parker 
Fellow, ibid., 1874-75; Universities of 
Berlin and Leipzig, 1871-75; Ph.D., 
University of Leipzig, 1875 ; Tutor of 
Mathematics, Harvard University, 1875- 
76 ; Associate, Assistant Professor, and 
Associate Professor of Mathematics, 
Johns Hopkins University, 1876-89 ; As- 
sociate Editor in Charge, American .Jour- 
nal of Mathematics, 1878-82 ; Professor 
of Mathematics, Clark University, 



Published Papers. 



547 



1889- ; Editor, Mathematical Review, 
1896-. 

Author of: — 

On the Algebraic Relations existing be- 
tween the Polars of a Binary Quantic. 
Dissertation approved for the degree of 
Ph.D., Leipzig, 1875. 58 pp. 

On the Elastic Potential of Crystals. Am. 
Jour, of Math., 1878, Vol. 1, pp. 177- 
183. 

Note on Mr. Kempe's Paper on the Geo- 
graphical Problem of the Jour Colors. 
lUd., 1879, Vol. 2, pp. 201-204. 

Note on the "15" Puzzle. Ibid., 1879, 
Vol. 2, pp. 399-404. 

On the Theory of Rational Derivation on a 
Cubic Curve (followed by a Note on 
Totients). Ibid., 1880, Vol. 3, pp. 
356-387. 

On the Non-Euclidean Trigonometry. 
Ibid., 1881, Vol. 4, pp. 332-335. 

On the Non-Euclidean Geometry. Ibid., 
1882, Vol. 5, pp. 180-211. 

On Non-Euclidean Properties of Conies. 
Ibid., 1882, Vol. 5, pp. 358-381. 

On the Absolute Classification of Quadratic 
Loci, and on their Intersections with 
each other and with Linear Loci. 
Ibid., 1885, Vol. 7, pp. 222-245. 

The Addition-Theorem for Elliptic Func- 
tions. Ibid., 1886, Vol. 8, pp. 364- 
375. 

A New Method in Analytic Geometry. 
Ibid., 1887, Vol. 9, pp. 38-44. 

On the Covariants of a System of Quan- 
tios. Math. Annalen, 1898, Vol. 41, 
pp. 469-490. 

On an Operator that produces all the Co- 
variants and Invariants of any System 
of Quantics. Proc. London Math. 
Soc, 1892, Vol. 23, pp. 265-272. 

Hyperspace and Non-Euclidean Geometry. 
I. Mathematical Beview, April, 1897, 
Vol. 1, pp. 169-184. 

J. RICHARD STREET: — 

A.B., Victoria University, 1884; A.M., 
ibid., 1888 (with First Honors in English, 
French, German, and Italian) ; Modem 
Language Master, Smithville High School, 



1885-86; Walkerton High School, 1886- 
87 ; Principal Caledonia High School, 
Ontario, 1887-95 ; Associate Member of 
the Board of Government Examiners, 
1891-95 ; Member and Secretary of the 
County Board of Examiners for Profes- 
sional Teachers' Certificates, 1889-95 ; 
Sometime Examiner in English, French, 
and German for Albert, Alma, and Brant- 
ford Colleges ; Instructor in the Mechanics 
Institute, Caledonia, 1893-95 ; Scholar 
in Pedagogy, Clark University, 1895- 
96 ; Fellow in Psychology, 1896-98; 
Ph.D., Clark University, 1898; Pro- 
fessor of Pedagogy, Bible Normal College, 
Springfield, Mass., 1898- ; also Prof essor of 
Theory and Practice of Teaching, Mount 
Holyoke College, 1899-. 

Author of : — 

A Study in Language Teaching. Peda- 
gogical Seminai-y, April, 1897, Vol. 4, 
pp. 209-293. 

A Study in Moral Education. Ibid., July, 
1897, Vol. 5, pp. 5-40. 

A Genetic Study of Immortality. Ibid., 
Sept., 1899, Vol. 6, pp. 267-313. 

Linguistic Interpretation. (In press.) 

CHARLES A. STRONG: — 

A.B., University of Rochester, 1884 ; A.B., 
Harvard University, 1885 ; Rochester 
Theological Seminary, 1885-86; Fellow, 
Harvard University, 1886-87 ; University 
of Berlin, 1886-87 ; Instructor in Philoso- 
phy, Cornell University, 1887-89 ; Uni- 
versities of Paris, Berlin, and Freiburg, 
1889-90 ; Decent in Philosophy, Clark 
University, 1890-91 ; Associate Pro- 
fessor of Psychology, University of Chi- 
cago, 1892-95 ; Lecturer in Psychology, 
Columbia University, 1895-. 

Author of : — 

A Sketch of the History of Psychology 
among the Greeks. Am. Jour, of Psy. , 
Dec, 1891, Vol. 4, pp. 177-197. 

Dr. Mtinsterberg's Doctrine of Mind and 
Body and its Consequences. Philo- 
sophical Beview, March, 1892, Vol. 1, 
pp. 179-195. 



548 



Titles of 



Mr. James Ward on Modern Psychology. 
Psychological Review, Jan., 1894, Vol. 

I, pp. 73-81. 

The Psychology of Pain. Ibid., July, 

1895, Vol. 2, pp. 329-347. 

Physical Pain and Pain Nerves. Ihid., 

Jan., 1896, Vol. 3, pp. 64-68. 
Consciousness and Time. Ibid., March, 

1896, Vol. 3, pp. 149-157. 

CHARLES K. S-WARTZ: — 

A.B., Johns Hopkins University, 1888; 
University of Heidelberg, 1888-89; Fel- 
low in Chemistry, Clark University, 
1889-90 ; Gettysburg Theological Semi- 
nary, 1890-91 ; Oberlin Theological Semi- 
nary, 1891-92 ; B.D., ibid., 1892 ; Pastor, 
Congregational Church, Bellevue, O., 
1892-. 

HENRY TABER:— 

Ph.B., Yale University (Sheffield Scien- 
tific School), 1882 ; Johns Hopkins Univer- 
sity, 1882-85 and 1886-88 ; Ph.D., Johns 
Hopkins University, 1888 ; Assistant in 
Mathematics, ibid., 1888-89; Docent in 
Mathematics, Clark University, 1889- 
92; Assistant Professor of Mathe- 
matics, 1892- ; Resident Fellow Ameri- 
can Academy of Arts and Sciences ; 
Member : London Mathematical Society ; 
American Mathematical Society. 

Author of: 

On the Theory of Matrices. Am. Jour. 

of Math., July, 1890, Vol. 12, pp. 337- 

396. 
On the Application to Matrices of any 

order of the Quaternion Symbols S and 

V. Froc. London Math. Soc, Dec. 

II, 1890, Vol. 22, pp. 67-79. 

On Certain Identities in the Theory of 
Matrices. Am. Jour, of Math., Jan., 
1891, Vol. 13, pp. 159-172. 

On Certain Properties of Symmetric, 
Skew Symmetric, and Orthogonal 
Matrices. Proc. London Math. Soc, 
June 11, 1891, Vol. 22, pp. 449-469. 

On the Matrical Equation (pQ = Qrj>. Proc. 
A. A. A. 8., 1891, Vol. 26, pp. 64-66. 

On a Theorem of Sylvester's relating to 



Non-Degenerate Matrices. Ibid. , 1892, 
Vol. 27, pp. 46-55. 

Note on the Representation of Orthogonal 
Matrices. Ibid., 1892, Vol. 27, pp. 
163-164. 

On the Linear Transformations between 
Two Quadrics. Proc. London Math. 
Soc, May 11, 1893, Vol. 24, pp. 290- 
306. 

On Real Orthogonal Substitution, Proc 
A. A. A. S; 1893, Vol. 28, pp. 212-221. 

On Orthogonal Substitution. Mathemat- 
ical papers read at International Math- 
ematical Congress, Chicago, 1893. 
Macmillan & Co., N. Y., 1896. pp. 
395-400. 

On Orthogonal Substitutions that can be 
expressed as a Function of a Single 
Alternate (or Skew Symmetric) Linear 
Substitution. Am. Jour, of Math., 
Jan., 1894, Vol. 16, pp. 123-130. 

On Orthogonal Substitutions. Bull. N. T. 
3Iath. Soc, July, 1894, Vol. 3, pp. 251- 
259. 

On the Automorphic Linear Transforma^ 
tion of a Bilinear Form. Proc A. A. 
A. S., 1894, Vol. 29, pp. 178-179. 

On the Group of Automorphic Linear 
Transformations of a Bilinear Form. 
Ibid., pp. 371-381. 

On those Orthogonal Substitutions that 
can be generated by the Repetition of 
an Infinitesimal Orthogonal Substitu- 
tion. Proc London Math. Soc, May 
9, 1895, Vol. 26, pp. 364-376. 

On the Automorphic Linear Transforma- 
tion of an Alternate Bilinear Form. 
Math. Annalen, 1895, Vol. 46, pp. 561- 
583. 

On Certain Sub-Groups of the General 
Projective Group. Bull. Am. Math. 
Soc, April, 1896, 2d ser., Vol. 2, pp. 
221-233. 

On a Twofold Generalization of Stieltje's 
Theorem. Proc. London Math. Soc, 
June 11, 1896, Vol. 27, pp. 613-621. 

Note on the Special Linear Homogeneous 
Group. Bull. Am. Math. Soc, July, 
1896, 2d ser.. Vol. 2, pp. 336-339. 

Note on the Automorphic Linear Trans- 
formation of a Bilinear Form. Proc 



Published Papers. 



549 



A. A. A. 8., 1896, Vol. 31, pp. 181- 
192. 

On the Group of Real Linear Transforma- 
tions whose Invariant is an Alternate 
Bilinear Form. Ibid., pp. 336-337. 

Notes on the Theory of Bilinear Forms. 
Bull. Am. Math. Soc, Jan., 1897, 2d 
ser. , Vol. 3, pp. 156-164. 

On the Transformations between Two 
Symmetric or Alternate Bilinear Forms. 
Mathematical Beview, April, 1897, Vol. 
1, pp. 120-126. 

On the Group of Linear Homogeneous 
Transformations whose Invariant is a 
Bilinear Form. /6M., pp. 154-168. 

On the Group of Real Linear Transforma- 
tions whose Invariant is a Real Quad- 
ratic Form. Proc. A. A. A. 8., 1897, 
Vol. 32, pp. 77-88. 

ROBERT R. TATNAIiL: — 

S.B., Haverford College, 1890; A.M., 
ibid., 1891 ; Graduate Student, Johns 
Hopkins University, 1891-93 ; Fellow and 
Assistant in Physics, Northwestern Uni- 
versity, 1893-94 ; Graduate Student, Johns 
Hopkins University, 1894-95; Ph.D., 
Johns Hopkins University, 1895 ; In- 
structor in Physics, University of Penn- 
sylvania, 1895-97 ; Honorary Fellow in 
Physics, Clark University, 1897-98; 
Instructor in Physics, Academy of North- 
western University, 1899-. 

Author of : — 

A New Proof of the Fundamental Equa^ 
tion of the Spectrometer. (Note by 
Professor Crew in Astronomy and 
Astrophysics, 1892, pp. 932-933.) 

On a New Method for Mapping the 
Spectra of Metals. (With H. Crew.) 
Philosophical Magazine, Oct., 1894, 
5th ser.. Vol. 38, pp. 379-386. 

The Arc-Spectra of the Elements. (With 
H. A. Rowland.) Astrophysical Jour- 
nal, Jan., Feb., and Oct., 1895, and 
April, 1896. 

SAMUEL N. TAYLOR: — 

Ph.B. , Wesleyan University, Middletown, 
Conn., 1887 ; In Charge of Experi- 



mental Laboratory, Thompson-Houston 
Electric Works, Lynn, Mass., 1887-91 ; 
Professor of Natural Sciences, Maine 
WesleyaiU Seminary and Female College, 
1891-93- Fellow in Physics, Clark 
University, 1893-96; Ph.D., Clark 
University, 1896 ; Instructor in Physics, 
Purdue University, 1896-99 ; Associate 
Professor of Physics, Syracuse Univer- 
sity, 1899- ; Member of Indiana Acad- 
emy of Science. 

Author of : — 

A Comparison of the Electromotive Force 
of the Clark and Cadmium Cells. 
Physical Beview, Sept.-Oct., 1898, 
Vol. 7, pp. 149-170. 

CHARLES HERBERT THURBER: — 

Ph.B., Cornell University, 1886; A.M., 
Haverford College, 1890 ; Registrar and 
Secretary, Cornell University, 1886-88 ; 
Teacher, Haverford College Grammar 
School, 1888-90; Special Agent U. S. 
Bureau of Education in Germany, 1890- 
91 ; Student, Royal Polytechnicum, Dres- 
den, 1890-91 ; Instructor in French, 
Cornell University, 1891-93 ; Professor of 
Pedagogy, Colgate University, and Princi- 
pal, Colgate Academy, 1893-95 ; Director 
of Division of Child Study, Department 
of Public Instruction, State of New York, 
1895-96 ; Assistant to Editor-in-chief, 
Johnson's " Universal Cyclopaedia," 1892- 
94 ; Editor, 8chool Beview, 1893- ; Editor, 
Transactions of Illinois Society for Child 
8tudy, 1898-99; Dean of the Morgan 
Park Academy, Sept., 1895-April, 1899 ; 
Associate Professor of Pedagogy, Uni- 
versity of Chicago, 1895- ; Director of 
Co(3perating Work, ihid., April, 1899; 
Honorary Fellow in Pedagogy, Clark 
University, Jan.-April, 1899. 

Author of : — 

The Cohesive Forces in American Nation- 
ality. Cornell Beview, 1886, Vol. 13, 
pp. 303-307. 

The Higher Schools of Prussia and the 
School of Conference of 1890. Bep. 
of the ComW of Ed., 1889-90, Vol. 1, 
pp. 313-418. 



550 



Titles of 



School Eeform in Germany. Academy, 
AprU, 1891, Vol. 6, p. 92. 

A History Lesson in German. Jour, of 
Education, Sept. 29, 1892, Vol. 36, pp. 
202-203. 

Editor, L'or o el'orpeUo. (Heath's Modem 
Language Series.) Boston, 1893. 68 pp. 

Summer Meetings. School Beview, Sept., 
1894, Vol. 2, pp. 480-438. 

The N. E. A. at Denver. School Beview, 
Sept., 1895, Vol. 3, pp. 422-433. 

Keport of ChDd Study Division, De- 
partment of Public Instruction, State 
of New York, 1895. 

Tabular Statement of Entrance Require- 
ments to Representative Colleges and 
Universities of the United States. 
(With W. J. Chase.) School Beview, 
June, 1896, Vol. 4, pp. 341-414. 

College Entrance Requirements. Proc. 
Ass^n Colleges and. Preparatory Schools 
of the Middle States and Maryland. 
Philadelphia meeting, 1896. 

High School Self -Government. School 
Beview, Jan., 1897, Vol. 5, pp. 32-35. 

The Report of the Committee of Ten. 
School Journal, June, 1897. 

Brennende Fragen in dem Uuterrichtswe- 
sen der Vereinigten Staaten. Detitsche 
Zeitschrift fur Auslandisches Unter- 
richtswesen, July, 1897, Vol. 2, pp. 
281-289. 

The Relation of Child Study to Sunday 
School Work. Northioestern Monthly, 
Sept., 1897, Vol. 8, pp. 137-141. 

Is the Present High-School Course a Satis- 
factory Preparation for Business ? If 
not, how should it be modified ? Proc. 
N. E. A., 1897, pp. 808-818. 

Die Sekundarschulen. Baumeister's Hand- 
buch der Erziehungs- tmd Unterrichts- 
lehre, 1897, Vol. 1, part II., pp. 589- 
604. 

Report of the Department of Child Study. 
Be}'). State Super. Pub. Instr., Albany, 
N. Y., 1897, Vol. 2, pp. 881-991. 

English as it is taught. School Beview, 
May, 1898, Vol. 6, pp. 328-338. 

Plans for the Development of Child Study 
in the State through the State Depart- 
ment. Trans. Til. Soc. for Child 



Study, Jan., 1899, Vol. 3, pp. 195- 
198. 

Vittorino da Feltre. School Beview, May, 
1899, Vol. 7, pp. 295-300. 

The New Courses in Pedagogy. Madison- 
ensis. Vol. 25, pp. 175-176. 

The Field and Work of a College Chris- 
tian Association. New Era, Vol. 5, 
p. 16. 

Hints on Child Study. Dep. Pub. Tnstr., 
State of New York. 

Numerous signed biograpWoal and edu- 
cational articles in Johnson's "Univer- 
sal Cyclopaedia" (new edition), 1892- 
94; 1898-99. 

Editor of "Twentieth Century" Text- 
Books. 

FRXnSERICK TRACY: — 

Pickering College, 1883-85; B.A., Uni- 
versity of Toronto, 1889 ; Fellow in Phi- 
losophy, ibid., 1889-92 ; Fellow in Psy- 
chology, Clark University, 1892-93 ; 
Ph.D., Clark University, 1893 ; Lec- 
turer in Philosophy, University of Toronto, 
1893- ; Member Illinois Society for Child 
Study; President Ontario Child Study 
Association. 

Author of : — 

The Testimony of Consciousness. Wood- 
stock Col. Mon., March, 1891. 

The Language of Children. Proc. Int. 
Ed. Congress, 1893. 

The Psychology of Childhood. D. C. 
Heath & Co., Boston, 1893. 2d ed., 
1894. 

The New Psychology. Can. Meth. Mag., 
Nov., 1894. 

The Scottish Philosophy. Univ. of To- 
ronto Quar., Nov., 1895. 

Hypnotism. Can. Meth. Mag., Nov., 
1895. 

Results of Child Study applied to Educa- 
tion. Trans. 111. Soc. for Child Study, 
1895, Vol. 1, No. 4, p. 12. 

Child Study and Pedagogy. Proc. Ont. 
Ed. Ass'n, 1895. 

Character as a Product of Education in 
Schools. Overland Monthly Publishing 
Co., 1896. 



Published Papers. 



551 



A Syllabus of Psychology. Toronto, 

1896. 
The Culture of the Spiritual Life. Mc- 

Master Univ. Mon., Jan., 1897. 
Die Kinderpsyohologie in England und 

Nord- America. Die Kinderfehler, April 

and July, 1897, Vol. 2, pp. 33-42, 

72-87. 
Results of Child Study. N. T. School 

Jour., July 10, 17, and 24, 1897. 
Left-handedness. Trans. HI. Soc. for 

Child Study, 1897, Vol. 2, pp. 68- 

76. 
Child Study, its Practical Value. Proc. 

Ont. Ed. Ass'n, 1897. 
Sully's "Studies of Childhood." Ibid., 

1898. 
Psyohologie der Kindheit. Translated by 

J. Stimpfl. E. Wunderlich, Leipzig, 

1899. 158 pp. 

NORMAN TRIPLETT : — 

A.B., Illinois College, 1889 ; Principal 
New Berlin, 111., School, 1889-91 ; Prac- 
tised Law, ibid., 1891-94 ; Instructor 
in Physics, Chemistry, and Psychology, 
Quincy, 111., High School, 1894-97 ; A.M., 
Indiana University, 1898 ; FeUovT- in Psy- 
chology, Clark University, 1898-99. 

Author of : — • 

The Dynamogenio Factors in Pacemaking 
and Competition. Am. Jour, of Fsy., 
July, 1898. Vol. 9, pp. 607-533. 

FREDERICK TUCKERMAN: — 

B.S., Boston Uniyersity, 1878; M.D., 
Harvard Medical School, 1882; Student, 
London and Berlin, 1882-83 ; Lecturer in 
Anatomy and Physiology, Massachusetts 
Agricultural College, 1883-86 ; Fellow in 
Vertebrate Anatomy, Clark Univer- 
sity, 1889-90 ; Student, Universities of 
Berlin, London, and Heidelberg, 1892-94; 
A.M. and Ph.D., University of Heidel- 
berg,1894; Private Laboratory at Amherst, 
Mass. , 1894- ; Fellow of the Massachusetts 
Medical Society, 1883-95; Member of: 
American Society of Naturalists, Boston 
Society of Natural History, Anatomical 
Society of Germany, etc. 



Author of : — 

Some Observations in Reference to Bilat- 
eral Asymmetry of Form and Function. 
Jour. Anat. and Phys., 1885, Vol. 19, 
pp. 307-308. 

Supernumerary Leg in a Male Frog (Rana 
palustris). Ibid., 1886, Vol. 20, pp. 
516-519, PI. xvi. 

The Tongue and Gustatory Organs of Me- 
phitis mephitica, Quar. Jour. Micr. 
Sci., 1887, Vol. 28, pp. 149-167, PI. 
xi. 

The Tongue and Gustatory Organs of Fiber 
zibethicus. Jour. Anat. and Phys., 
1888, Vol. 22, pp. 135-141, PI. vii. 

Note on the Papilla f oliata and other Taste 
Areas of the Pig. Anat. Anzeiger, 
1888, Vol. 3, pp. 69-73. 

An Interesting Specimen of Taenia sagi- 
nata. Zool. Anzeiger, 1888, Vol. 11, 
pp. 94-95. 

The Anatomy of the Papilla f oliata of the 
Human Infant. Jour. Anat. and Phys., 
1888, Vol. 22, pp. 499-501, PI. xviii. 

Antipyrine in Cephalalgia. N. T. Med. 
Pecord, 1888, p. 180. 

Observations on the Structure of the Gus- 
tatory Organs of the Bat (Vespertilio 
subulatus). Jour. ofMorph., 1888,Vol. 
2, pp. 1-6, PI. i. 

Supplementary Note on Taenia saginata. 
Zool. Anzeiger, 1888, Vol. 11, pp. 473- 
475, figures. 

Anthropometric Data Relating to Students 
of the Massachusetts Agricultural Col- 
lege. Amherst, 1888. 

On the Gustatory Organs of Putorius vi- 
son. Anat. Anzeiger, 1888, Vol. 3, pp. 
941-942. 

On the Gustatory Organs of Vulpes vul- 
garis. Jour. Anat. and Phys., 1889, Vol. 
23, pp. 201-205. 

On the Gustatory Organs of Arctomys mo- 
nax. Anat. Anzeiger, 1889, Vol. 4, pp. 
334-335. 

On the Development of the Taste-Organs 
of Man. Jour. Anat. and Phys., 1889, 
Vol. 23, pp. 559-582. 

On the Gustatory Organs of Soiurus caro- 
linensis. Microscope, 1889, Vol. 9, pp. 
193-196, PI. vii. 



552 



Titles of 



On the Gustatory Organs of Erethizon dor- 
satus. Am. Mo. Micr.Joiir., 1889, Vol. 
10, p. 181. 

An Hitherto Undescribed Taste Area in 
Perameles nasuta. Anat. Anzeiger, 

1889, Vol. 4, pp. 411-412, figure. 

On the Gustatory Organs of the American 

Hare(Lepus americanus). Am. Jour. 

of Sci., 1889, Vol. 38, pp. 277-280. 
Note on the Tongue of Chrysotis ^estiva. 

Microscope, 1889, Vol. 9, pp. 289-290. 
The Gustatory Organs of Belideus ariel. 

Jour. Anat. and Phys., 1889, Vol. 24, 

pp. 85-88, PL V. 
Further Observations on the Development 

of the Taste-Organs of Man. Ibid., 

pp. 130-131. 
The Gustatory Organs of Procyon lotor. 

Ibid., pp. 156-159, PI. x. 
On the Gustatory Organs of the Mammalia. 

Proc. Boston So. Nat. Hist., 1890, Vol. 

24, pp. 470-482. 
On the Gustatory Organs of some Eden- 
tata. Internat. Monats. f. Anat. u. 

Phys., 1890, Vol. 7, pp. 335-339. 
On the Gustatory Organs of some of the 

Mammalia. Jour. ofMorph., 1890, Vol. 

4, pp. 151-193. 
The Development of the Gustatory Organs 

in Man. Am. Jour, of Psy., April, 

1890, Vol. 3, pp. 195-197. 

On the Gustatory Organs of Soiurus hud- 
sonius. Internat. Monats. f. Anat. 
u. Phys., 1891, Vol. 8, pp. 137-139, 
PL xi. 

Observations on some Mammalian Taste- 
Organs. Jour. Anat. and Phys., 1891, 
Vol. 25, pp. 505-508. 

On the Terminations of the Nerves in the 
Lingual Papillae of the Chelonia. In- 
ternat. Monats. f. Anat. u. Phys., 1892, 
Vol. 9, pp. 1-5, PI. i. 

The Gustatory Organs of Ateles ater. 
Jour. Anat. and Phys., 1892, Vol. 26, 
pp. 391-393. 

Further Observations on the Gustatory 
Organs of the Mammalia. Jour, of 
Morph., 1892, Vol. 7, pp. 69-94. 

Note on the Structure of the Mammalian 
Taste-Bulb. Anat. Anzeiger, 1893, Vol. 
8, pp. 366-367. 



The Development of the Organs of Taste. 
Reference Hand-book of the Medical 
Sciences, 1893, Vol. 9, pp. 857-859, fig- 
ures, 600-607. 

JOHN N. VAN DEH TRIES : — 

A.B., Hope College, 1896; Principal of 
School, East Saugatuck, Mich., 1896-97; 
Scholar in Mathematics, Clark TTni- 
versity, 1897-98 ; Fellow, 1898-99. 

FRANK L. O. "WADS'WORTH: — 

E.M., Ohio State University, 1888; M.E., 
ibid., 1889; B.S., ibid., 1889; Assistant 
in Physics, ibid., 1888-89; Fellow in 
Physics, Clark University, 1889-90; 
Fellow and Assistant, 1890-92 ; 
Special Assistant and Delegate from 
the Smithsonian Institution to the Bu- 
reau Internationale des Poids et Mesures, 
Paris, 1892 ; Senior Assistant in Charge, 
Astrophysical Observatory, Smithson- 
ian Institution, 1892-94; Assistant Pro- 
fessor in Physics, University of Chicago, 
1894-96 ; Assistant Professor of Astro- 
physics, Yerlves Observatory, 1896-97 ; As- 
sociate Professor of Astrophysics, ibid., 
1897-98 ; Special Engineering and Expert 
Work, Pittsburg and Washington, 1898- 
99 ; Director of the Allegheny Observa- 
tory, May, 1899- ; Assistant Editor, As- 
trophysical Journal; Associate Editor, 
Harper'' s Scientific Memoirs ; Member As- 
tronomical and Astrophysical Society of 
America. 

Author of : — 

Some New Forms of Dynamos. Electrical 
World, Sept. 13, 1890, Vol. 16, pp. 183- 
184. 

On the Relation between Rise of Temper- 
ature and Current in Electric Conduc- 
tors. Ibid., Feb. 27, 1892, and March 
12, 1892, Vol. 19, pp. 145-146, 180- 
181. 

Application of Interference Methods to 
Base Line Measurement. Philosophi- 
cal Society, Washington, Nov., 1892. 

Report of the Smithsonian Astrophysical 
Observatory. Smithsonian Ann. Bep., 
Appendix V., 1893, pp. 60-67. 



Published Papers. 



553 



Electric Controls and Governors for Astro- 
nomical Instruments. Astronomy and 
Astrophysics, April, 1894, Vol. 13, pp. 
265-272. 

A Simple Method of determining the Ec- 
ceiitrioity of a Graduated Circle with 
One Vernier. Am. Jour. ofSci., May, 
1894, 3d ser., Vol. 47, pp. 373-376. 

The Manufacture of Very Accurate Straight 
Edges. Jour, of the Franklin Institute, 
July, 1894, Vol. 20, pp. 138. Ke- 
printed in Amencan Machinist, Aug. 
2, 1894. 

An Improved Eorm of Littrov? Spectro- 
scope. Philosophical Magazine, July, 
1894, 5th ser.. Vol. 38, pp. 137-142. 

A New Design for Large Spectroscope Slits. 
Am. Jour, of Sci., July, 1894, 3d ser., 
Vol. 48, pp. 19-20. 

Some New Double Motion Mechanisms. 
Astronomy and Astrophysics, Aug., 

1894, Vol. 13, pp. 527-528. Reprinted 
in Zeits. f. Instrumentenkunde, Jan., 

1895, Vol. 15, pp. 32-35. 

Fixed Arm Spectroscopes. Philosophical 
Magazine, Oct., 1894, 5th ser., Vol. 38, 
pp. 337-351. Reprinted in Astronomy 
and Astrophysics as No. 9 of the series. 
The Modern Spectroscope, Dec, 1894, 
Vol. 13, pp. 835-849. 

Ein neuer Spektroskopspalt mit Doppel- 
bewegung. Zeits. f. Instrumenten- 
kunde, Oct., 1894, Vol. 14, pp. 364-366. 

A Simple Method of mounting an Equa- 
torial Axes on Ball Bearings. As- 
tronomy and Astrophysics, Nov., 1894, 
Vol. 13, pp. 723-728. 

A New Method of magnetizing and asta- 
tizing Galvanometer Needles. Philo- 
sophical Magazine, Nov., 1894, 5th 
ser., Vol. 38, pp. 482-488. 

An Improved Eorm of Interrupter for 
Large Induction Coils. Am. Jour, of 
Sci., Dec, 1894, 3d ser., Vol. 48, 
pp. 496-501. 

Description of a Very Sensitive Eorm of 
Thomson Galvanometer and Some 
Methods of Galvanometer Construc- 
tion. Philosophical 3fagazine, Dec, 
1894, 5th ser., Vol. 38, pp. 553-558. 

General Considerations respecting the 



Design of Astronomical Spectroscopes. 
Forming No. 10 of the series, The 
Modern Spectroscope. Astrophysical 
Journal, Jan., 1895, Vol. 1, pp. 52-79. 

Bemerkungen iiher Versilberungsfliissig- 
keiten und Versilberung. Zeits. f. 
Instrumentenkunde, Jan., 1895, Vol. 
15, pp. 22-27. Reprinted in the Astro- 
physical Journal, March, 1895, Vol. 1, 
pp. 252-260. 

The Design of Electric Motors for Con- 
stant Speed. Astrophysical Journal, 
Feb., 1895, Vol. 1, pp. 169-177. 

Some New Designs of Combined Grating 
and Prismatic Spectroscopes of the 
Fixed Arm Type and a New Eorm of 
Objective Prism. Forming No. 11 of 
the series, The Modern Spectroscope. 
Ibid., March, 1895, Vol. 1, pp. 232- 
247. 

Einfaoher Unterkrecher fiir grosse Induk- 
tionsapparate. Zeits. f. Instrumenten- 
kunde, July, 1895, Vol. 15, pp. 248- 
250. 

A New Multiple Transmission Prism of 
Great Resolving Power. No. 13 of the 
series. The Modern Spectroscope. As- 
trophysical Journal, Nov., 1895, Vol. 
2, pp. 264-282. 

Fixed Arm Concave Grating Spectro- 
scopes. No. 14, The Modern Spectro- 
scope. Ibid., Dec, 1895, Vol. 2, pp. 
370-382. 

A Very Simple and Accurate Cathe- 
tometer. Am. Jour, of Sci, Jan., 1896, 
Vol. 1, pp. 41-49. Reprinted in Phil- 
osophical Magazine, Feb., 1896, Vol. 
41, 123-133. 

The Use and Mounting of the Concave 
Grating as an Analyzing or Direct 
Comparison Spectroscope. No. 15, 
The Modem Spectroscope. Astro- 
physical Journal, Jan., 1896, Vol. 3, 
pp. 47-62. 

A Simple Optical Device for completely 
isolating or cutting out any Desired 
Portion of the Diffraction Spectrum 
and Some Further Notes on Astro- 
nomical Spectroscope. No. 16, The 
Modern Spectroscope. Ibid., March^ 
1896, Vol. 3, pp. 149-192. 



554 



Titles of 



A Note on Mr. Burch's Method of Draw- 
ing Hyperbolas and on a New Hyper- 
bolagraph. Philosophical Magazine, 
April, 1896, Vol. 41, pp. 372-378. 

Review of Boy's Work on the Newtonian 
Constant of Gravitation. Astrophysical 
Journal, April, 1896, Vol. 3, pp. 303- 
311. 

The Conditions of Maximum Efficiency in 
the Use of the Spectrograph. No. 18, 
The Modern Spectroscope. Ihid., May, 
1896, Vol. 3, pp. 321-347. 

Review of Langley's Report on the Smith- 
sonian Astrophysical Observatory for 

1895. Ihid., May, 1896, Vol. 3, pp. 
398-401. 

The Objective Spectroscope. No. 19, The 
Modern Spectroscope. Ibid., June, 

1896, Vol. 4, pp. 54^78. 

Review of Professor Stoney's paper on the 
Equipment of the Astrophysical Ob- 
servatory of the Future. Ibid., Oct., 
1896, Vol. 4, pp. 238-243. 

A Note on the Preparation of Phosphores- 
cent Barium Sulphide. Ibid., Nov., 
1896, Vol. 4, pp. 308-309. 

A Note on a Combined Equatorial Tele- 
scope and Polar Heliostat. Ibid. , Nov., 

1896, Vol. 4, p. 310. 

On a New Form of Mounting for Reflect- 
ing Telescopes, devised by the late 
Arthur Cowper Ranyard. Ibid., Feb., 

1897, Vol. 5, pp. 1.32-142. 

A Note on a New Form of Fluid Prism. 
Ibid., Feb., 1897, Vol. 5, p. 149. 

On the Resolving Power of Telescopes 
and Spectroscopes for Lines of Finite 
Width, ilemorie della Societa degli 
Spettroscopisti Italiani, Jan., 1897, 
Vol. 26, pp. 2-22. Philosophical Maga- 
zine, May, 1897, Vol. 43, pp. 317-343. 

Thermal Measurements with the Bolo- 
meter by the Zero Method. Astro- 
physical Joxirnal, April, 1897, Vol. 5, 
pp. 268-276. 

The Application of the Interferometer to 
the Measurement of Small Angular 
Deflections of a Suspended System. 
Physical Review, May-June, 1897, 
Vol. 4, pp. 480-497. 

Tables of the Practical Resolving Power 



of Spectroscopes. Astrophysical Jour- 
nal, June, 1897, Vol. 6, pp. 27-36. 

Ueber das Auflosungsvermogen von Fern- 
rohren and Spectroskopen fiir Linien 
von endlicher Breite. Ann. der Physik 
u. Chemie, June, 1897, Vol. 61, pp. 
604-6.30. 

On the Conditions which determine the 
Limiting Time of Exposure of Photo- 
graj)hic Plates in Astronomical Pho- 
tography. Ast7-onomische Nachrichten, 
Vol. 144, pp. 97-110. 

The Effect of the General Illumination of 
the Sky on the Brightness of the 
Field at the Focus of a Telescope. 
Monthly Notices of Boy al Astronomical 
Soc, Jime, 1897, Vol. 57, pp. 586-589. 

A Note on Spider Lines. Ibid. , pp. 589- 
591. 

On the .Conditions which determine the 
Ultimate Optical Efficiency of Methods 
for observing Small Rotations, and on 
a Simple Method of doubling the Ac- 
curacy of the Mirror and Scale Method. 
Philosophical Magazine, July, 1897, 
Vol. 44, pp. 83-97. 

On the Conditions of Maximum Efficiency 
in Astrophilographic Work. Part I. 
General Theory of Telescopic Images 
of Different Forms of Radiating 
Sources. Astrophysical Journal, Aug., 
1897, Vol. 6, pp. 119-135. 

A Comparison of the Photographic and 
of the Hand and Eye Methods of de- 
lineating the Surface Marking.s of 
Celestial Objects. Popular Astron- 
omy, Aug., 1897, Vol. 5, pp. 200-206. 

Astronomical Photography. Knowledge, 
Aug. and Sept., 1897, Vol. 20, pp. 193- 
195, 218-221. 

A Note on the Effect of Heat on Phos- 
phorescence. Astrophysical Journal, 
Aug., 1897, Vol. 6, pp. 153-155. 

Adam Hilger. Ibid., pp. 139-141. 

Review of Dr. Braun's Die Gravitations 
Constante die Masse und mittlere 
Dichte der Erde. Ibid., pp. 157-163. 

Sur le Pouvoir S^parateur des Lunettes et 
de Spectroscopes pour les Raies de 
Largeur Finie. Jour, de Physique, 
Aug., 1897, VoL 6, pp. 409. 



Published Papers. 



555 



A Determination of the Specific Resist- 
ance and Temperature Coefficient of 
Oil in Tliin Films and the Application 
of these Eesults to the Measurement 
of the Thickness of OU Films in Jour- 
nal Bearings. Physical Beview, Aug., 
1897, Vol. 5, pp. 75-97. 

On the Photography of Planetary Sur- 
faces. Observatory, Sept., Oct., Nov., 
1897, Vol. 20, pp. 333-341, 365-370, 
404-410. 

On the Conditions required for attaining 
Maximum Accuracy in the Determina- 
tion of Specific Heat by the Method of 
Mixtures. Am. Jour, of Sci., Sept., 
1897, Vol. 4, pp. 265-282. 

On the Effect of the Size of an Objective 
on the Visibility of Linear Markings 
on the Planets. Astronomical Jour- 
nal, Oct. 6, 1897, Vol. 18, pp. 41- 
45. 

On the Reduction of Observations. Ob- 
sermtory, Oct. 1897, Vol. 20, pp. 390- 
392. 

Note on the General Theory of Telescopic 
Images. Astrophysieal Journal, Dec, 

1897, Vol. 6, p. 463. 

On the Theory of Lubrication and the 
Determination of the Thickness of the 
Film of Oil in Journal Bearings. Jour, 
of Franklin Institute, Dec, 1897, Jan., 

1898, Vols. 144^145. 

On the Conditions of Maximum Efficiency 
in Astrophilographic Work. Part II. 
Effect of Atmosjjheric Aberration on 
the Intensity of Telescopic Images. 
Astrophysieal Journal, Jan., 1898, 
Vol. 7, pp. 70-76. 

A Note on the Discovery of an Error in 
the Papers of Struve and Lord Ray- 
leigh dealing with the Application of 
the Principles of the Wave Theory to 
the Determination of the Intensity of 
the Images of Fine Lines and Ex- 
tended Areas at the Focus of a Tele- 
scope. Astrophysieal Journal, Jan., 
1898, Vol. 7, pp. 77-85. 

A Note on an Error in the Expression for 
the Intensity of Illumination at the 
Focal Plane of a Telescope due to an 
Infinitely Extended Luminous Area. 



Astronomical Journal, Jan., 1898, Vol. 
18, pp. 124-126. 

A Note on a New Form of Mirror for Re- 
flecting Telescopes. Popular Astron- 
omy, Feb., 1898, Vol. 5, pp. 518-524. 

On the ' ' Worthlessness ' ' of Methods of 
Geometrical Optics in deahng with the 
Problems relating to the Definitive 
and the Delineating and Resolving 
Power of Telescopes. Ibid., pp. 528- 
536. 

A Note on the Figuring and Use of 
Eccentric and Unsymmetrical Forms 
of Parabolic Mirrors. Astrophysieal 
Journal, Feb., 1898, Vol. 7, pp. 146- 
149. 

A Note on the Result concerning Dif- 
fraction Phenomena recently criticised 
by Mr. Newall. Monthly Notices of 
Boyal Astronomical 8oe., March, 1898, 
Vol. 58, pp. 286-291. 

Notes on the Use of the Grating in Stellar 
Spectroscopic Work. Astrophysieal 
Journal, March, 1898, Vol. 7, pp. 198- 
208. 

CHARLES WALKER: — 

B.C.E., University of Tennessee, 1885; 
M.A., ibid., 1886 ; Assistant Professor 
of Chemistry and Physics, ibid., 1886- 
88 ; Assistant in Chemistry, U. S. Naval 
Academy, Annapolis, 1889-90 ; FelloTW 
in Chemistry, Clark University, 1890- 
93 ; Professor of Chemistry and Physics, 
Wisconsin State Normal School, 1893-94 ; 
Professor of Natural Science, Carson- 
Newman College, Mossy Creek, Tenn. , 
1898-. 

Author of : — 

Oxidation of Meta-Brom Toluene and Ni- 
trotoluene Sulphamide. (With Dr. 
W. A. Noyes.) Am. Chem. Jour., 
June, 1886, Vol. 8, pp. 185-190. 

Oxidation of Para-xylene Sulphamide. 
(With Dr. W. A. Noyes.) Ibid., 
April, 1887, Vol. 9, pp. 93-99. 

The Condensation-Products of Acetacetic- 
ether Hydrazide and Oxalciticether 
Hydrazide. Ibid., Dec, 1892, Vol. 
14, pp. 576-586. 



556 



Titles of 



The Condensation-Products of Aromatic 
Hydrazydes of Aoetaoiticether. Indol 
and Pyrazol Derivations. Ibid., June, 
1894, Vol. 16, pp. 430-442. 

On tlie Action of Potassium Hydroxide 
on Orthomethoxysulphaminebenzoio 
Acid. Ihid., 1897, Vol. 19, pp. 578- 



ARTHUR J. "WARNER: — 

A.B., Marietta College 0., 1889; A. 
M., ibid., 1897; Scholar in PhysicB, 
Clark University, 1889-90 ; Engaged in 
Electrical Work, Johns Hopkins Univer- 
sity, 1890-92 ; Certificate in Electrical 
Engineering, ibid., 1892 ; With the Cher- 
okee Mining Co., Chute, Ga., 1898-. 

SHO WATASE : — 

B.S., Sapporo, Japan, 1884; Student of 
Zoology, University of Tokio, 1884-86 ; 
Fellow in Biology, Johns Hopkins Univer- 
sity, 1888-89; Bruce Fellow, ibid., 1889- 
90; Ph.D., Johns Hopkins University, 
1890 ; Lecturer and Assistant in Mor- 
phology, Clark University, 1890-92; 
Header in Cellular Biology, University 
of Chicago, 1892-9.3 ; Instructor in Anat- 
omy and Physiology of the Cell, ibid., 
1893-95 ; Assistant Professor in Cellular 
Biology, ibid., 1895-99 ; Professor of 
Cellular Biology, Imperial University, 
Tokio, Japan, 1899-. 

Author of : — 

Caryokinesis and the Cleavage of the 
Ovum. J. H. U. Circulars, April, 

1890, Vol. 9, pp. 53-56. 

On the Morphology of the Compound 
Eyes of Arthropods. Quar. Jour, of 
Micr. Sci., June, 1890, N. S., Vol. 31, 
pp. 143-158, 1 pi. 

On Caryokinesis. Woods Soil Biological 
Lectures, 1890. Ginn & Co., Boston, 

1891, pp. 168-187. 

Studies on Cephalopoda. I. Cleavage of 
the Ovum. Journal of Morphology, 
Jan., 1891, Vol. 4, pp. 247-302, 4 pis. 

The Origin of the Sertoli's Cell. Ameri- 
can Naturalist, May, 1892, Vol. 26, 
pp. 442-444. 



On the Signiflcance of Spermatogenesis. 
Ibid., July, 1892, Vol. 26, pp. 624-626. 

On the Phenomena of Sex Differentiation. 
Jour, of MorpJi. , J-alj, 1892, Vol. 6, pp. 
481-493. 

Homology of the Centrosome. Ibid., 
May, 1893, Vol. 8, pp. 433-444. 

On the Nature of Cell Organization. 
Woods Soil Biological Lectures, 1893. 
Ginn & Co., Boston, 1894, pp. 83-103. 

Origin of the Centrosome. Ibid., 1894. 
Ginn & Co., Boston, 1895, pp. 273-287. 

On the Physical Basis of Animal Phos- 
phorescence. Ibid., 1895. Ginn & 
Co., Boston, 1896, pp'. 101-118. 

Microsomes and their Eelation to the 
Centrosome. Science, Feb. 5, 1897, 
N. S., Vol. 5, pp. 230-281. 

Protoplasmic Contractibility and Phos- 
phorescence. Ibid., 1898. (In press.) 

OLIVER P. "WATTS: — 

A.B., Bowdoin College, 1889 ; A.M., 
ibid., 1892; Scholar in Chemistry, 
Clark University, 1889-90 ; Instructor 
in Physics, Chemistry, and Mathematics, 
Franklin Academy, Malone, N. Y., 1892- 
98 ; Instructor in Physics, High School, 
Waltham, Mass., 1898-. 

ARTHUR GORDON "WEBSTER:- 

A.B., Harvard University, 1885; In- 
structor in Mathematics, ibid., 1885-86; 
Parker Fellow, ibid., 1886-89; Student, 
Universities of Berlin, Paris, and Stock- 
holm, 1886-90 ; Ph.D., University of Ber- 
lin, 1890 ; Docent in Physics, Clark 
University, 1890-92 ; Assistant Pro- 
fessor of Physics, 1892- ; Resident 
Fellow, American Academy of Arts and 
Sciences ; Fellow, American Association 
for the Advancement of Science ; Mem- 
ber: American Mathematical Society, 
American Physical Society. 

Author of : — • 

Versuche tiber sine Methode zur Bestim- 
mung des Verhaltnisses der elektro- 
magnetischen zur elektrostatischen 
Einheit der Elektricitat. (Inaugural- 
dissertation.) Berlin, 1890. 



Published Papers. 



557 



A National Physical Laboratory. Peda- 
gogical Seminary, June, 1892, Vol. 2, 
pp. 90-101. 

Unipolar Induction and Current without 
Difference of Potential. Electrical 
World, April 14-21, 1894, Vol. 23, 
pp. 491-492, 523-524. 

On a Means of producing a Constant An- 
gular Velocity. Am. Jour, of Sci., 
May, 1897, Vol. 3, pp. 379-382. 

A Rapid Break for Large Currents. Ibid. , 
pp. 388-386. 

A New Instrument for measuring the In- 
tensity of Sound. (With B. F. Sharpe. ) 
Beport British A. A. *S., Toronto, 1897, 
p. 584. Also Proc. A. A. A. S., Bos- 
ton, 1898, p. 136. 

The Theory of Electricity and Magnetism, 
being Lectures on Mathematical Phys- 
ics. Macmillan & Co., London, 1897. 
563 pp. 

An Experimental Determination of the 
Period of Electrical Oscillations. 
(Elihu Thomson Prize, Paris, 1895.) 
Physical Bevieio, May-June, 1898, Vol. 
6, pp. 297-314. 

Note on Stokes's Theorem in Curvilinear 
Coordinates. Bull. Am. Math. Soc, 
June, 1898, 2d ser., Vol. 4, pp. 438- 
441. 

A New Chronograph and a Means of 
Rating Tuning-forks. Proc. A. A. A. 
S., Boston, 1898, p. 13G. 

A Geometrical Method for Investigating 
Diffraction by a Circular Aperture. 
Ibid., p. 136. 

Report on the State of the Mathematical 
Theory of Electricity and Magnetism. 
Ibid., pp. 103-112. Also Science, Dec. 
9, 1898, Vol. 8, pp. 803-810. 

Ten Lowell Institute Lectures on Elec- 
tricity and Magnetism, Light, and the 
Ether, 1897. 

Six Lectures for the Colloquium of the 
American Mathematical Society, 1898. 

JULIUS B. -WEEMS: — 

B.S., Maryland Agricultural College, 
1888 ; Instructor in Chemistry and Mathe- 
matics, ibid., 1888-89; Student, Johns 
Hopkins University, 1889-91 ; Chemist at 



Phosphate Mines, Florida, 1891-92 ; Fel- 
low in Chemistry, Clark University, 
1892-94 ; Ph.D., Clark University, 
1894 ; On Special Research at New York 
Experiment Station, Geneva, N. Y., Oct., 
1894-March, 1895 ; Professor of Agricul- 
tural Chemistry, Iowa State College of 
Agriculture and Mechanic Arts, and 
Chemist, Iowa Experiment Station, Ames, 
la., March, [1895- ; Chemist, Iowa Geo- 
logical Survey, Jan., 1899- ; Member: 
German Chemical Society, American 
Chemical Society, Society of Chemical 
Industry of London, Society for Promo- 
tion of Agricultural Science, American 
Academy of Political and Social Science ; 
Fellow, Iowa Academy of Science. 

Author of : — 

On Electrosyntheses by the Direct Union 

of Anions of Weak Organic Acids. 

Am. Chem. Jour., Dec, 1894, Vol. 

16, pp. 569-588. 
The Chemical Composition of Squirrel-tail 

Grass. Iowa Experiment Station 

Bull., No. 30, pp. 320-321. 
Studies on Milk Preservatives. Ibid. , No. 

32, pp. 499-504. 
Soil Moisture. Ibid., No. 32, pp. 505-515. 
The Adulteration of Food. Mep. of State 

Dairy Com. of Iowa, 1895, pp. 212-216. 
Soil Moisture. Iowa Experiment Station 

Bull., No. 36, pp. 825-848. 
Milk Preservatives. III. State Dairyman's 

Ass'n, 1898, pp. 103-110. 
Chemistry and some of its Relations to 

Agriculture. Bep. of the Iowa State 

Agric. Soc, 1898, pp. 42-48. 

GERALD M. -WEST: — 

A.B., Columbia College, 1888; A.M., 
ibid., 1889; Ph.D., Columbia College, 
1890 ; Fellow in Anthropology, Clark 
University, 1890-91 ; Assistant in 
Anthropology, 1891-92 ; First Assist- 
ant in Anthropology, Bureau of Ethnology, 
World's Columbian Exposition, 1892-93 ; 
Decent in Ethnology, University of 
Chicago, 1893-95 ; Curator of Physical 
Anthropology, Field Columbian Museum, 
Chicago, 1894. 



558 



Titles of 



Author of: — 

The Status of the Negro in Virginia during 
the Colonial Period. (Thesis for the 
Doctorate.) New York, 1890. 76 pp. 

The Growth of the Breadth of the Face. 
Science, July 3, 1891, Vol. 18, pp. 10- 
11. 

Eye-Tests on School Children. Am. Jour, 
of Psy., Aug., 1892, Vol. 4, pp. 595- 
596. 

The Growth of the Body, Head, and Face. 
Science, Jan. 6, 1893, Vol. 21, pp. 2-4. 

The Anthropometry of American School 
Children. Mem. Internat. Congress of 
Anthropology, 1893 (Chicago, 1894), 
pp. 50-58. 

Anthropometrische Untersuchungen tiber 
die Schulkinder in Worcester, Mass., 
Amerika. Arch. f. Anthropologic, 
Braunschweig, 1893,Vol. 22, pp. 13-48. 

The Growth of the Human Body. Edu- 
cational Review, Oct., 1896, Vol. 12, 
pp. 284-289. 

Observations on the Relation of Physical 
Development to Intellectual Ability, 
made on the School Children of To- 
ronto, Canada. Science, Aug. 7, 1896, 
N. S., Vol. 4, pp. 156-159. 

A. HARRY ■WTHEELER: — 

S.B., Worcester Polytechnic Institute, 
1894 ; Instructor in Mathematics, English 
High School, Worcester, 1894-Dec. , 1896 ; 
and 1899- ; Scholar in Mathematics, 
Clark University Dec, 1896-June, 
1899. 

"WILLIAM MORTON WHEELER: — 

Graduate, German and English Academy, 
Milwaukee, Wis., 1880 ; Graduate German- 
American Normal College, Milwaukee, 
Wis., 1883; Ward's Natural Science Es- 
tablishment, Rochester, N. Y., 1883-85; 
Teacher of German and Assistant in Biol- 
ogy, Milwaukee Public High School, 1885- 
88; Curator, Milwaukee Public Museum, 
1887-90; FeUow and Assistant in 
Morphology, Clark University, 1890- 
92; Ph.D., Clark University, 1892; 
Student at the University of Wurzburg 
and University of Li^ge ; Occupant of the 



Smithsonian Table at the Zoological Sta- 
tion, Naples, 1893-94; Instructor in Em- 
bryology, University of Chicago, 1892-95 ; 
Assistant Professor of Embryology, ibid. , 
1895-99 ; Professor of Zoology, University 
of Texas, 1899. 

Author of : — 

Spiders of the Sub-family Lyssomanae. 
(With G. W. and E. G. Peokham.) 
Trans. Wis. Acad. Science, Arts and 
Letters, Vol. 7, 1888, pp. 222-256, Pis. 
xi. and xii. 

On Two New Species of Cecidomyid Flies 
producing GaUs on Antennaria planta^ 
ginifolia. Proc. Wis. Nat. Hist. Soc, 
April, 1889, pp. 209-216. 

Two Cases of Insect Mimicry. Ibid., pp. 
217-221. 

Ueber driisenartige GebUde im ersten Ab- 
dominal-segment der Hemipterenem- 
bryonen. Zool. Anzeiger, 1889, 12 
Jahrg., pp. 500-504, 2 fig. 

Homologues in Embryo Hemiptera of the 
Appendages to the First Abdominal 
Segment of other Insects. American 
Naturalist, 1889, pp. 644-645. 

The Embryology of Blatta germanica and 
Doryphora decem-lineata. Jour, of 
Morph., Sept., 1889, Vol. 3, pp. 291- 
386, 7 pi. 

On the Appendages of the First Abdomi- 
nal Segment of Embryo Insects. Wis. 
Acad. Science, Arts and Letters, Sept. 
20, 1890, Vol. 8, pp. 87-140, Pis. !.- 
iii. 

Ueber ein eigenthtlmliches Organ im Lo- 
custidenembryo. Zool. Anzeiger, 13 
Jahrg., 1890. 

Note on the Oviposition and Embryonic 
Development of Xiphidium ensiferum 
Scud. Insect Life, 1890, Vol. 2, pp. 
222-225. 

Descriptions of Some New North American 
Doliohopodids. Psyche, 1890, Vol. 1, 
pp. 3.37-343, 356-362, 373-379. 

The Supposed Bot-fly Parasite of the Box- 
Turtle. Ibid., 1890, Vol. 1, p. 403. 

Hydrocyanic Acid secreted by Polydesmus 
virginiensis Drury. Ibid., 1890, Vol. 1, 
p. 442. 



Published Papers. 



559 



The Embryology of a Common Fly. Ibid., 
1891, Vol. 2, pp. 97-99. 

The Germ-band of Insects. Ibid., 1891, 
Vol. 2, pp. 112-115. 

Neuroblasts in the Arthropod Embryo. 
Jour. ofMorph., Jan., 1891, Vol. 4, pp. 
337-343, 1 fig. 

Concerning the "Blood-tissue " of the In- 
secta. Ibid., 1892, Vol. 2, pp. 216-220, 
233-236, 253-258, PI. vii. 

A Contribution to Insect Embryology. 
(Inaugural Dissertation.) Jour, of 
Morph., April, 1893, Vol. 8, pp. 1-160, 
6 pis. 

The Primitive Number of Malpighian Ves- 
sels in Insects. Psyche, 1893, Vol. 2, 
pp. 457-460, 485-486, 497-498, 509-510, 
539-541, 545-547, 561-564, 2 figs. 

Syncoelidium pellucidum, a New iVIarine 
Triclad. Jour. ofMorph., April, 1894, 
Vol. 9, pp. 167-194, 1 pi. 

Planocera inquilina, a Polyclad inhabiting 
the Branchial Chamber of Syootypus 
canaliculatus Gill. Ibid., April, 1894, 
Vol. 9, pp. 195-201, 2 figs. 

Protandrio Hermaphroditism in Myzo- 
stoma. Zool. Anzeiger, 17 Jahrg., 
1894. 

The Behavior of the Centrosomes in the 
Fertilized Egg of Myzostoma glabrum 
Leuckart. Jour, of Wlorph., Jan., 
1895, Vol. 10, pp. .305-311. 

The Problems, Methods, and Scope of 
Developmental Mechanics. (Trans- 
lated from the German of Wilhelm 
Eoux.) Biological Lectures, Marine 
Biological Laboratory, Woods HoU, 
1895, pp. 149-190. 

The Sexual Phases of Myzostoma. Mitth. 
a. d. Zool. Station zu Neapel, 1896, 
Vol. 12, pp. 227-302. Pis. x.-xii. 

The Genus Ochthera. Entomological 
News, April, 1896, Vol. 7, pp. 121- 
123, 1 fig. 

Two Dolichopodid Genera New to Amer- 
ica. Ihid., May, 1896, Vol. 7, pp. 152- 
156. 

A New Genus and Species of Dolicho- 
podidK. Ibid., June, 1896, Vol. 7, 
pp. 185-189, 1 fig. 

A New Empid with Remarkable Middle 



Tarsi. Ibid., June, 1896, Vol. 7, pp. 
189-192, 3 figs. 

An Antenniform Extra Appendage in 
Dilophus tibialis Loew. Arch. f. Ent- 
wick. Mech. d. Organismen, 1896, Vol. 
3, pp. 261-268, PI. xvi. 

The Maturation, Fecundation, and Early 
Cleavage of Myzostoma glabrum 
Leuckart. Arch, de Biologic, 1897, 
Vol. 15, pp. 1-77, Pis. i.-ui. 

A Genus of Maritime Dolichopodidse New 
to America. Proc. Cal. Acad. Sci., 
Zool, July, 1897, 3d ser., Vol. 1, pp. 
145-152. PI. iv. 

A New Genus of Dolichopodid® from 
Florida. Zoological Bulletin, Feb., 
1898, Vol. 1, pp. 217-220, 1 fig. 

A New Peripatus from Mexico. Jour, of 
Morph., Oct., 1898, Vol. 15, pp. 1-8, 1 pi. 

George Baur's Life and Writings. Amer- 
ican Naturalist, Jan., 1899, Vol. 33, 
pp. 15-30. 

Anemotropism and Other Tropisms in 
Insects. Arch. f. Entwick. Mech. d. 
Organismen, 1899, Vol. 8, pp. 373-381. 
New Species of Dolichopodidse from the 
United States. Proc. Cal. Acad. Sci., 
Zool., 3d ser, Sept., 1899, Vol. 2, pp. 
1-77, Pis. i.-iv. 

The Development of the Urinogenital Or- 
gans of the Lamprey. Zool. Jahr- 
bucher, Abth. f. Morph., 1899, Bd. 13, 
pp. 1-88, Pis. i.-vii. 

The Life-History of Dicyema. Zool. An- 
zeig., April, 1899, Vol. 22, pp. 169-176. 

J. Beard on the Sexual Phases of Myzos- 
toma. Ibid., July, 1899, Vol. 22, pp. 
281-288. 

Caspar Friedrich Wolff and the Theoria 
Generationis. Biological Lectures, 
Marine Biological Laboratoiy, Woods 
Holl, 1899. 

GUY MONTROSE "WHIPPLE: — 

A.B., Brown University, 1897 ; Scholar 
and Assistant in Psychology, Clark 
University, 1897-98 ; Assistant in Psy- 
chology, Cornell University, 1898-. 
Author of : — 

The Influence of Forced Eespiration on 
Psychical and Physical Activity. Am. 



560 



Titles of 



Jour, of Psy., July, 1898, Vol. 9, pp. 
560-571. 
On Nearly Simultaneous Clicks and 
Flashes. Ibid., Jan., 1899, Vol. 10, 
pp. 280-286. 

HENRY S. ■WHITE : — 

A.B., Wesleyan University, 1882 ; Assistant 
in Astronomy and Physics, ib^d., 1882-83 ; 
Instructor in Mathematics, Hackettstown, 
N. J., 1883-84; Tutor in Mathematics, 
Wesleyan University, 1884^87 ; Ph.D., 
University of Gbttingen, 1890 ; Assistant 
in Mathematics, Clark University, 
1890-92 ; Associate Professor of Mathe- 
matics, Northwestern University, 1892-94; 
Noyes Professor of Pure Mathematics, 
ibid., 1894- ; Member American Mathe- 
matical Society. 

Author of : — 

Ueber zwei covariante Formen aus der 
Theorie der Abel'schen Integrale 
auf voUstandigen, singularitatenfreien 
Schnittcurven zweier Flacheu. Math. 
Annalen, 1890, Vol. 36, pp. 597-601. 

Abel'sche Integrale auf singularitaten- 
freien, einfach iiberdeckten, voUstan- 
digen Schnittcurven eines beliebig 
ausgedehnten Raumes. Nova Acta 
Leop.-Carol. Akad., 1891, Vol. 67, pp. 
41-128. 

On generating Systems of Ternary and 
Quaternary Linear Transformations. 
Am. Jour, of Math., July, 1892, Vol. 
14, pp. 274-282. 

A Symbolic Demonstration of Hilbert's 
Method for deriving Invariants and 
Covariants of Given Ternary Forms. 
Ibid., pp. 283-290. 

Review of Klein's Evanston Lectures. 
Bull. N. Y. Math. Soc, Feb. 1894, 
Vol. 3, pp. 119-122. 

Eeduction of the Resultant of a Binary 
Quadric and n-ic by Virtue of its Semi- 
combinant Property. Ibid. , Oct., 1894, 
Vol. 1, pp. 11-15. 

Semi-combinants as Concomitants of Af- 
filiants. Am. Jour, of Math., July, 
1895, Vol. 17, pp. 235-265. 

Kronecker'sLinear Relation among Minors 



of a Symmetric Determinant. Bull. 

Am. Math. Soc, Feb., 1896, Vol. 2, 

pp. 136-138. 
Numerically Regular Reticulations upon 

Surfaces of Deficiency higher than 1. 

Ibid., Dec, 1896, Vol. 3, pp. 116- 

121. 
The Cubic Resolvent of a Binary Quartic 

Derived by Invariant Definition and 

Process. Ibid., April, 1897, Vol. 3, 

pp. 250-253. 
CoUineations in a Plane with Invariant 

Quadric or Cubic Curves. Ibid., Oct., 

1897, Vol. 4, pp. 17-23. 
Inflexional Lines, Triplets, and Triangles 

associated with the Plane Cubic Curve. 
Ibid., March, 1898, Vol. 4, pp. 258- 
260. 

The Construction of Special Regular Re- 
ticulations on a Closed Surface. Ibid. , 
May, 1898, Vol. 4, pp. 376-382. 

Elliott's Algebra of Quantics. Review. 
Ibid., July, 1898, Vol. 4, pp. 545-549. 

The Cambridge Colloquium. Ibid., Oct., 

1898, Vol. 5, pp. 57-58. 

Report on the Theory of Projective Invar 
riants ; the Chief Contributions of a 
Decade. Ibid., Jan., 1899, Vol. 5, pp. 
161-175. 

CHARLES O. WHITMAN: — 

A.B., Bowdoin College, 1868; Principal 
Westford Academy and Master in the 
English High School, Boston, 1869-75; 
Ph.D., University of Leipzig, 1878 ; Fel- 
low, Johns Hopkins University, 1878-79 ; 
Professor of Zoology, Imperial University 
of Japan, 1880-81 ; Naples Zoological 
Station, 1881-82 ; Director, Allis Lake 
Laboratory, 1886-89 ; Director, Marine 
Biological Laboratory, Woods Holl, Mass., 
1888- ; Professor of Animal Morphol- 
ogy, Clark tJniversity, 1889-92 ; Head 
Professor of Zoology, University of 
Chicago, 1892- ; Editor of: Journal of 
Morphology, 1887- ; Biological Lectures 
from the Marine Biological Laboratory, 
Woods Holl, Mass., 1890- ; American 
Naturalist, Department of Microscopy, 
1883-96 ; Zoological Bulletin, 1897-99 
(continued in Biological Bulletin, 1899-). 



Published Papers. 



561 



Author of : — 

The Embryology of Clepsine. Quar. 
Jour. Micr. Set, 1878, Vol. 18, pp. 
215-315. 

Ueber die Embryologie von Clepsine. 
Zool. Anzeiger, 1878, Vol. 1, pp. 5-6. 

Changes Preliminary to Cleavage. Proc. 
A. A. A. S., 1878, Vol. 27, pp. 263- 
270. 

Do Flying Fish Fly ? American Natural- 
ist, Sept., 1880, Vol. 14, pp. 641-653. 

Zoology in the University of Tokio, Yoko- 
hama, 1881, pp. 1-44. 

Methods of Microscopical Research in the 
Zoological Station of Naples. Ameri- 
can Naturalist, Sept., 1882, Vol. 16, 
pp. 697-785. 

A New Species of Branchiobdella. Zool. 
Anzeiger, Sept. 10, 1882, Vol. 5, pp. 1-2. 

The Advantages of Study at the Naples 
Zoological Station. Science, July 27, 
1883, Vol. 2, pp. 93-97. 

A Kare Form of the Blastoderm of the 
Chick, and its Bearing on the Question 
of the Formation of the Vertebrate 
Embryo. Quar. Jour. Micr. Sci., 

1883, Vol. 23, pp. 375-397. 

A Contribution to the Embryology, Life- 
History, and Classification of the Di- 
cyemids. Mitth. aus d. Zool. Station 
von Neapel, Jan. 23, 1883, Vol. 4, pp. 
1-89, 5 pis. 

On the Development of some Pelagic Fish 
Eggs. (With Alexander Agassiz.) 
Proc. Am. Acad. Arts and Sciences, 

1884, N. S., Vol. 12, pp. 23-75. 

The External Morphology of the Leech. 

(With Alexander Agassiz.) Ibid., 

1884, N. S., Vol. 12, pp. 76-87. 
The Connective Substance in the Hira- 

dinea. American Naturalist, Oct., 

1884, Vol. 18, pp. 1070-1071. 
The Segmental Sense-Organs of the 

Leech. Ibid., Nov., 1884, Vol. 18, 

pp. 1104-1109. 
The Pelagic Stages of Young Fishes. 

(With Alexander Agassiz.) Mem. 

Mus. Camp. Zoology, 1885, Vol. 14, 

pp. 1-56. 
Methods in Microscopical Anatomy and 

Embryology. Boston, 1885. 255 pp. 
2o 



The Germ-Layers of Clepsine. Zool. 

Anzeiger, 1886, Vol. 1, pp. 1-6. 
The Leeches of Japan. Quar. Jour. 
Micr. Set, April, 1886, Vol. 26, pp. 
317-416. 5 pis. 
Biological Instruction in Universities. 
American Naturalist, June, 1887, Vol. 
21, pp. 507-519. 
A Contribution to the History of the 
Germ-Layers in Clepsine. Jour, of 
Morph., Sept., 1887, Vol. 1, pp. 105- 
182, 3 pis. 
The Kinetic Phenomena of the Egg 
during Maturation and Fecundation. 
Ibid., Dec, 1887, Vol. 1, pp. 227- 
252. 
The Seat of Formative and Regenerative 
Energy. Ibid., July, 1888, Vol. 2, 
pp. 27-49. 
Address at the opening of the Marine 
Biological Laboratory, July 17, 1888. 
First Annual Beport for the Year 
1888, pp. 24-31. 
The Development of Osseous Fishes. 
(With Alexander Agassiz.) II. The 
Preembryonic Stages of Development. 
Part I. The History of the Egg from 
Fertilization to Cleavage. Mem. Mtis. 
Comp. Zoology, 1889, Vol. 14, pp. 
1-40. 
Some New Facts about the Hirudinea. 
Jour, of Morph., April, 1889, Vol. 2, 
pp. 586-599. 
Specialization and Organization, Compan- 
ion Principles of all Progress. The 
Most Important need of American Bi- 
ology. Woods Holt Biological Lec- 
tures, 1890. Ginn & Co., Boston, 1891, 
pp. 1-26. 
The Naturalist's Occupation. Ibid., 1890. 

Ginn & Co., Boston, 1891, pp. 27-52. 
Spermatophores as a Means of Hypoder- 
mic Impregnation. Jour, of Morph., 
Jan., 1891, Vol. 4, pp. 361^06, 1 pi. 
Description of Clepsine Plana. Ibid., pp. 

407-418, 1 pi. 
Metamerism of Clepsine. LeuckarVs 

Festschrift, 1892, pp. 385-395. 
The Marine Biological Laboratory, Fri- 
day Chapel Address. University News, 
Chicago, Dec. 17^ 1892. 



562 



Titles of 



General Physiology and its Relations to 
Morphology. Fifth Annual Beport 
Marine Biological Laboratory, 1892. 
Reprinted in American Naturalist, 
Sept., 1893, Vol. 27, pp. 802-807. 

A IMarine Biological Observatory. Pop. 
Sci. Mo., Feb., 1893, Vol. 42, pp. 459- 
471. 
A Marine Observatory the Prime Need of 
American Biology. Atlantic Monthly, 
June, 1893, Vol. 71, pp. 808-815. 

A Sketch of the Structure and Develop- 
ment of the Eye of Clepsine. Spen- 
geVs Zool. Jahrbucher, 1893, Vol. 6, 
pp. 616-625. 

The Inadequacy of the Cell-Theory of De- 
velopment. Jour, of Morph., August, 

1893, Vol. 8, pp. 639-658 ; also Woods 
Soil Biological Lectures, 1893. Ginn 
& Co., Boston, 1894, pp. 105-124. 

The Work and the Aims of the Marine 
Biological Laboratory. Woods Soil 
Biological Lectures, 1893. Ginn & 
Co., Boston, 1894, pp. 235-242. 

Evolution and Epigenesis. Ibid., 1894. 
Ginn & Co., 1895, pp. 205-224. 

Bonnet's Theory of Evolution. Ibid., 

1894, Ginn & Co., 1895, pp. 225-240. 
The Palingenesia and the Germ Doctrine 

of Bonnet. 76i(?., 1894, Ginn & Co., 

1895, pp. 241-272. 

The Egg of Amia and its Cleavage. (With 
A. C. Eycleshymer.) Jour, of Morph., 
Feb., 1897, Vol. 12, pp. 309-354. 2 
pis. 

Some of the Functions and Features of a 
Biological Station. Presidential Ad' 
dress to the Society of American Nat 
uralists, Ithaca meeting, 1897. Woods 
Eoll Biological Lectures, 1896-97 
Ginn & Co., Boston, 1898, pp. 231- 
242 ; also in Science, Jan. 14, 1898 
Vol. 7, pp. 37-44. 

The Centrosome Problem and an Experi- 
mental Test. Science, Feb. 5, 1897 
N. S., Vol. 5, p. 67. 

Lamarck and "A Perfecting Tendency.' 
Ibid., Jan. 21, 1898, Vol. 7, p. 99. 

Apathy's Grief and Consolation. Zool 
Anzeiger, May 1, 1899, Vol. 22, pp 
196-197. 



Myths in Animal Psychology. Monist, 

July, 1899, Vol. 9, pp. 524-537. 
Animal Behavior. Woods Holl Biologi- 
cal Lectures, 1898, pp. 285-338. 

FRANK B. -WILLIAMS: — 

C.E., Missouri State University, 1890; 
M.S., ibid., 1893; Teaching Fellow in 
Mathematics, ibid., 1892-93; United 
States Assistant Engineer, Tennessee 
River Improvement, 1895-97 ; Scholar 
in Mathematics, Clark University, 
1897-98 ; Fellow, 1898-99. 

Author of: — 

Note on the Finite Continuous Groups of 
the Plane. Proc. Am. Acad, of Arts 
and Sci., Nov., 1899, Vol. 35, pp. 
97-107. 

J. FRANCIS -WILLIAMS: — 

C.E., Rensselaer Polytechnic Institute, 
1883 ; B.S., ibid., 1884 ; Ph.D., Univer- 
sity of Gottingen, 1886 ; University of 
Berlin, 1887 ; Director, Technical Museum 
of Pratt Institute, Brooklyn, N. Y., 1887- 
89 ; Decent in Mineralogy, Clark Uni- 
versity, 1889-90 ; Assistant Professor 
of Geology, Cornell University, 1890-91. 
Died Nov. 9, 1891. 

Author of : — 

Tests of Rutland and Washington County 
Slates. Van Nostrand's Eng. Mag., 
1884, No. 188. 

Ueber den Monte Amiata in Toscana und 
seine Gesteine. Stuttgart, 1887. 

Igneous Rooks of Arkansas. Annual Be- 
port of the Geological Survey, Arkan- 
sas, 1890, Vol. 2. 457 pp. Illustrated. 

ALBERT P. -WILLS: — 

B.E.E., Tufts College (with Honors in 
Electricity), 1894 ; Scholar in Physics, 
Clark University, 1894-95 ; Fellow, 
1895-Jan., 1897; Ph.D., Clark Uni- 
versity, 1897 ; Professor of Physical 
Sciences, Colorado State Normal School, 
Jan., 1897-June, 1898; Student in Phy- 
sios, Universities of Gottingen and Ber- 
lin, 1898-99 ; Associate in Applied 



Published Papers. 



563 



Mathematics and Physios, Bryn Mawr 
College, 1899-. 

Author of: — 

On the Susceptibility of Diamagnetic and 
weakly Magnetic Substances. Fhilo- 
sopMcal Magazine, May, 1898, 5th 
ser.. Vol. 45, pp. 432-147 ; also Physi- 
cal Beview, April, 1898, Vol. 6, pp. 
223-238. 

Moleculare Susceptibilitat paramagneti- 
scher Salze. (With 0. Liebkneoht.) 
Verhandl. der deuts. physik. Gesell- 
schaft, Sitz. vom 30 Juni, 1899 (to be 
published later in extenso). 
Zur thermometrisohen und kryogenen Ver- 
wendung des Kohlensaureschnees. 
(With H. du Bois.) Verhandl. der 
deuts. physik. Gesellschaft. Sitz. vom 
30 Juni, 1899. (To be published later 
in extenso.) 

On the Magnetic Shielding Effect of Tri- 
lamellar Spherical and Cylindrical 
Shells. Physical Review, Oct., 1899. 
Vol. 9, pp. 193-213. 

MINOSUKB YAMAGITCHI: — 

LL.B., Tokio Law School, 1892 ; Student 
in Philosophy, De Pauw University, 1894- 
97; A.B., Lombard University, 1897; 
Scholar in Psychology, Clark Univer- 
sity, 1897-98 ; Graduate Student, Yale 
University, 1898-99. 

ALBERT H. YODBR: — 

Teacher in Public Schools, Dakota, 1882- 
87 ; Graduate, State Normal School, 
Madison, So. Dak., 1888 ; Superintendent 
of Schools, ibid., 1888-91 ; A.B., Univer- 
sity of Indiana, 1893 ; Scholar in Peda- 
gogy, Clark University, 1893-94; 
Principal, San Francisco Normal School, 
1894-95 ; Scholar in Psychology, Univer- 
sity of Chicago, 1895-96 ; Specialist in 
Pediatrics, Northwestern University Medi- 
cal School, 1896 ; President of the Faculty 
and Professor of Philosophy and Peda- 
gogy, Vincennes University, 1896- ; Edi- 
tor of the Bulletin of the Preparatory 
Teachers' Department, Vincennes Univer- 
sity, Nov. 1896-. 



Author of : — 

The Study of the Boyhood of Great Men. 

Pedagogical Seminary, Oct., 1894, Vol. 

3, pp. 134-156. 
A Syllabus for the Study of Pubescence. 

Child Study Monthly, Feb., 1896, Vol. 

1, pp. 280-282. 

Investigations in Pubescence. Trans. III. 
Soc. for Child Study, 1897, Vol. 2, No. 

2, pp. 81-84. 

Pubescence. Northwestern Monthly, May, 
1898, Vol. 8, pp. 597-600. 

LBWIS BD-WIN YORK: — 

Tutor in Mathematics, Mt. Union College, 
1891-93 ; B.S., Mt. Union College, 1894 ; 
Superintendent of Public Schools, Newton 
Falls, 0., 1894-96 ; Graduate, King's 
School of Oratory, 1896 ; President Du- 
quesne College, 1896-97; Ph.D. (pro 
merito), Duquesne College, 1897 ; Scholar 
in Pedagogy, Clark University, 1897- 
98 ; Superintendent Public Schools, 
Kingsville, 0., 1898-. 

Author of:— - 

America's Need — Men. Plutocrat, Oct., 

1893. 
Thoughts on Oratory. Dynamo, Jan., 

1895. 

J. W. A. YOUNG: — 

A.B., Bucknell University, 1887 ; A.M., 
ibid., 1890 ; Instructor in Mathematics, 
Bucknell Academy, 1887-88 ; University 
of Berlin, 1888-89 ; Fellow in Mathe- 
matics, Clark University, 1889-92 ; 
Ph.D., Clark University, 1892 ; Asso- 
ciate in Mathematics, University of Chi- 
cago, 1892-94; Instructor in Mathematics, 
ibid., 1894-97 ; Assistant Professor of 
Mathematical Pedagogy, ibid. , 1897- ; In- 
vestigating Methods of Teaching Mathe- 
matics in Prussia, 1897-98 ; Member 
American Mathematical Society. 

Author of : — 

On the Determination of Groups whose 
Order is a Power of a Prime. Am. 
Jour, of Math., April, 1893, Vol. 15, 
pp. 124-178. 



564 



Titles of Published Papers. 



Bachmann's Theory of Numbers. Bull. 

N. Y. Math. Soc, June, 1894, Vol. 3, 

pp. 215-222. 
Theory of Numbers and of Equations. 

Bull. Am. Math. Soc, 1896, 2d ser.. 

Vol. 3, pp. 97-105. 
Zur mathematischen Lehrblicherfrage : 

Eine schulstatistische Untersuchung. 



Hoffmanii's Zeits. f. math. u. natur- 
wiss. Unterricht, Sept., 1898, Vol. 29, 
pp. 410-414. 
The Elements of the Differential and 
Integral Calculus. (With C. E. Line- 
barger.) D. Appleton & Co., New 
York. (In press.) 



SPECIAL STUDENTS AND MEMBEES OF THE 
SATURDAY TEACHERS' CLASS. 



[The positions here specified are those held while the incumbents were connected with the 
University.] 



Allen, Nellie B., Instructor, State Normal School, Fitchburg, Mass. „ ^ , ^ 

Andrews, Calvin H., Instructor in Physics and Mathematics, English High School, Worcester, 

Andrews 'waiter E., Instructor in Mathematics, English High School, Worcester, Mass. 
Benneyan H G., Pastor, Armenian Congregational Church, Worcester, Mass. 
BoYden Arthur C, Vice-Principal, State Normal School, Bridgewater, Mass. 
Brown, Anna L., Instructor, Northfield Training School, East Northfield, Mass. 
Buck Jonathan I., Principal, High School, Webster, Mass. 

Calkins, Mary Whlton, Assistant Professor of Philosophy, Wellesley CoUege, Wellesley, Mass. 
Carroll Clarence P., Superintendent of Schools, AVorcester, Mass. 
Casey Daniel H., Principal, Grafton Street School, Worcester, Mass. 
Childs', Anne Gertrude, Instructor, State Normal School, Oneonta, N. Y 
Clinton Mrs C W. (Candidate for A.B., University of Minnesota), Worcester, Mass. 
Cole Geor-e P., Instructor in Modern Languages, English High School, Worcester, Mass. 
Colvin, Stephen S., Instructor in English, English High School, Worcester, Mass. 
Dean, Harold M., Sub-master, High School, Webster, Mass. 
Defendorf Allen R., Interne at Worcester Insane Hospital, Worcester, Mass. 
Delano Charles W., Instructor, Classical High School, Worcester, Mass. 
Drake, Mary A., Principal, Washington Street School, Worcester, Mass. 
Edmund, Gertrude, Principal, Training School, Lowell, Mass. 
Eish Eachel C, Instructor, The Dalzell School, Worcester, Mass. 
Fla-ff Edward W., Instructor in English, State Normal School, Potsdam, N. Y. 
Goolwin, Edward R., Principal, Classical High School, Worcester Mass 
Gray, Albert, Instructor in Greek History, English High School, Worcester, Mass. 
Grout, Edgar H., Principal, High School, North Brookfield, Mass. 
tHale Abby C, Teacher, Downing Street School, Worcester, Mass. Died, May 1, 1899. 
Hale, Edward B., Principal, High School, Brookfield Mass. 
Halsey Lila S., Principal, Northfield Training School, East Northfield, Mass. 
Hamlin, Alice J. (A.B., Wellesley College), Lexington, Mass. 
Han.son, Charles L., Instructor, English High School, Worcester Mass. 
■ Haskeir Ellen M., Instructor, State Normal School, Worcester, Mass. 
Hayes, Grace L., Principal, Training School, Beverly, Mass. 

Hill Gershom H , Superintendent, Iowa Hospital, Independence, la. , tvt„.„ 

HowaM Er"n W., Assistant in Physics, Worcester Polytechnic Institute, Worcester, Mass. 

565 



566 Special Students. 

Howes, Bessie E., Assistant Superintendent of Scliools, Worcester, Mass. 

Hunt, Charles L., Superintendent of Schools, CUnton, Mass. 

Ignatios, A. Marderos, Smyrna, Turkey. 

Irving, Arthur P. , Superintendent of Schools, Ayer and "West Boylston, Mass. 

Jenkins, James, Principal, English High School, Worcester, Mass. 

Judkins, C. L., Principal High School, Oxford, Mass. 

Kempfer, J. E., Worcester, Mass. 

Keyes, Charles H., Principal, High School, Holyoke, Mass. 

Kimball, Albert B., Instructor in Physics, English High School, Worcester, Mass. 

Lindley, Mrs. E. H. (A.B., Indiana University), Bloomington, Ind. 

Lyman, C. S., Superintendent of Schools, Oxford, Mass. 

Miles, Caroline, Instructor in Psychology, Wellesley College, Wellesley, Mass. 

Mix, Grace E., Teacher, Salisbury Street Kindergarten, Worcester, Mass. 

Monroe, Will S., Instructor in Psychology and Pedagogy, State Normal School, Westfield, 

Mass. 
Naruse, Jinzo, Christian Ministry, Yamaguchi, Japan. 

Nelson , William, Graduate Student, Worcester Polytechnic Institute, Worcester, Mass. 
Olin, Arvin S., Superintendent of Schools, Kansas City, Kansas. 
Phelon, Joseph O., Instructor in Physics and Electrical Engineering, Worcester Polytechiuc 

Institute, Worcester, Mass. 
Pitman, J. Asbury, Superintendent of Schools, West Boylston District, Mass. 
Eice, Arthur L., Instructor in Mechanical Engineering, Worcester Polytechnic Institute, 

Worcester, Mass. 
Rust, Annie C, Principal, Kindergarten Normal School, Worcester, Mass. 
Search, Preston W., Superintendent of Schools, Holyoke, Mass. 
Smith, Clarissa W. (A.B., Bryn Mawr College), Worcester, Mass. 

Smith, Clayton 0., Assistant in Physics, Worcester Polytechnic Institute, Worcester, Mass. 
Smith, Ella L., Instructor, Classical High School, Worcester, Mass. 
Smith, Rev. H. W., Universalist Ministry, Worcester, Mass. 
Smith, Preston, Science Teacher, State Normal School, Fitchburg, Mass. 
Smith, Theodate L. (Candidate for Ph.D., Yale University), New Haven, Conn. 
Southgate, Hugh M., Assistant in Physics, Worcester Polytechnic Institute, Worcester, Mass. 
Stoddard, George H., Principal, High School, East Douglas, Mass. 
Thompson, Rev. W. J., Pastor, Grace M. E. Church, Worcester, Mass. 
Trumbull, Mary, Instructor, English High School, Worcester, Mass. 
Viets, Emily H., Teacher, Salisbury Street Kindergarten, Worcester, Mass. 
Waggener, W. J., Professor of Natural Philosophy, State University of Colorado, Boulder, Col. 
Watts, W. G., Student in Biology, Worcester, Mass. 
Wilmarth, Elmar H., Instructor, Manual Training High School, Worcester, Mass. 



89 



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